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Purification, characterization and thermal inactivation kinetics of a non-regioselective thermostable lipase from a genotypically identified extremophilic Bacillus subtilis NS 8

Olusesan AT, Azura LK, Forghani B, Bakar FA, Mohamed AK, Radu S, et al.

N Biotechnol, 2011 Oct;28(6):738-45.
PMID: 21238617 DOI: 10.1016/j.nbt.2011.01.002

Thermostable lipase produced by a genotypically identified extremophilic Bacillus subtilis NS 8 was purified 500-fold to homogeneity with a recovery of 16% by ultrafiltration, DEAE-Toyopearl 650M and Sephadex G-75 column. The purified enzyme showed a prominent single band with a molecular weight of 45 kDa. The optimum pH and temperature for activity of lipase were 7.0 and 60°C, respectively. The enzyme was stable in the pH range between 7.0 and 9.0 and temperature range between 40 and 70°C. It showed high stability with half-lives of 273.38 min at 60°C, 51.04 min at 70°C and 41.58 min at 80°C. The D-values at 60, 70 and 80°C were 788.70, 169.59 and 138.15 min, respectively. The enzyme's enthalpy, entropy and Gibb's free energy were in the range of 70.07-70.40 kJ mol(-1), -83.58 to -77.32 kJ mol(-1)K(-1) and 95.60-98.96 kJ mol(-1), respectively. Lipase activity was slightly enhanced when treated with Mg(2+) but there was no significant enhancement or inhibition of the activity with Ca(2+). However, other metal ions markedly inhibited its activity. Of all the natural vegetable oils tested, it had slightly higher hydrolytic activity on soybean oil compared to other oils. On TLC plate, the enzyme showed non-regioselective activity for triolein hydrolysis.

Matched MeSH terms: Bacillus subtilis/enzymology*; Bacillus subtilis/growth & development
Effect of signal peptides on the secretion of β-cyclodextrin glucanotransferase in Lactococcus lactis NZ9000

Subramaniam M, Baradaran A, Rosli MI, Rosfarizan M, Khatijah Y, Raha AR

J. Mol. Microbiol. Biotechnol., 2012;22(6):361-72.
PMID: 23295307 DOI: 10.1159/000343921

Cyclodextrin glucanotransferase (CGTase) is an extracellular enzyme which catalyzes the formation of cyclodextrin from starch. The production of CGTase using lactic acid bacterium is an attractive alternative and safer strategy to produce CGTase. In this study, we report the construction of genetically modified Lactococcus lactis strains harboring plasmids that secrete the Bacillus sp. G1 β-CGTase, with the aid of the signal peptides (SPs) SPK1, USP45 and native SP (NSP). Three constructed vectors, pNZ:NSP:CGT, pNZ:USP:CGT and pNZ:SPK1:CGT, were developed in this study. Each vector harbored a different SP fused to the CGTase. The formation of halo zones on starch plates indicated the production and secretion of β-CGTase by the recombinants. The expression of this enzyme is shown by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and zymogram analysis. A band size of ∼75 kDa corresponding to β-CGTase is identified in the intracellular and the extracellular environments of the host after medium modification. The replacement of glucose by starch in the medium was shown to induce β-CGTase production in L. lactis. Although β-CGTase production is comparatively low in NZ:SPK1:CGT, the SP SPK1 was shown to have higher secretion efficiency compared to the other SPs used in this study.

Matched MeSH terms: Bacillus/enzymology; Bacillus/genetics
Cloning of high activity xylanase gene from Bacillus pumilus PJ19

Hamzah A, Abdulrashid N

J. Biochem. Mol. Biol. Biophys., 2002 Oct;6(5):365-9.
PMID: 12385974

The xylanase gene from Bacillus pumilus PJ19 amplified by polymerase chain reaction (PCR) was cloned into pCRII vector and transformed into Escherichia coli strain INValphaF'. Starting from an ATG as an initiator codon, an open reading frame coding for 202 amino acids was obtained. The recombinant xylanase sequence showed a 96% homology with the xylanase sequence from B. pumilus IPO strain and had an estimated molecular weight of 22,474. Xylanase activity expressed by E. coli INValphaF' harboring the cloned gene was located primarily in the cytoplasmic fraction.

Matched MeSH terms: Bacillus/enzymology; Bacillus/genetics*
Does recovery in the spectral characteristics of GdnHCl-denatured Bacillus licheniformis α-amylase due to added calcium point towards protein stabilization?

Halim AA, Feroz SR, Tayyab S

Biosci Biotechnol Biochem, 2013;77(1):87-96.
PMID: 23291750

Treatment of Bacillus licheniformis α-amylase (BLA) with guanidine hydrochloride (GdnHCl) produced both denatured and aggregated forms of the enzyme as studied by circular dichroism, fluorescence, UV difference spectroscopy, size exclusion chromatography (SEC), and enzymatic activity. The presence of CaCl(2) in the incubation mixture produced significant recovery in spectral signals, being complete in presence of 10 mM CaCl(2), as well as in enzymatic activity, which is indicative of protein stabilization. However, the SEC results obtained with GdnHCl-denatured BLA both in the absence and the presence of 10 mM CaCl(2) suggested significant aggregation of the protein in the absence of CaCl(2) and disaggregation in its presence. Although partial structural stabilization with significant retention of enzymatic activity was observed in the presence of calcium, it was far from the native state, as reflected by spectral probes. Hence, spectral results as to BLA stabilization should be treated with caution in the presence of aggregation.

Matched MeSH terms: Bacillus/enzymology; Bacillus/chemistry*
Fulltext A preliminary study of the bioactivity of vegetative proteins extracted from Malaysian Bacillus thuringiensis isolates

Ramasamy B, Nadarajah VD, Soong ZK, Lee HL, Mohammad SM

Trop Biomed, 2008 Apr;25(1):64-74.
PMID: 18600206

Vegetative proteins from Malaysian strains of Bacillus thuringiensis israelensis strains (Bt 11, Bt 12, Bt 15, Bt 16, Bt 17, Bt 21 and Bt 22) and Bacillus sphaericus H-25 strains (Bs 1 and Bs 2) were screened for haemolytic, cytotoxic and larvicidal activity. SDS-PAGE profiles of the Bacillus thuringiensis strains studied consistently showed major bands of 33-37 kDa and 47 kDa. Bt 16 also showed two bands of 66 kDa and 45 kDa similar to the previously reported binary vegetative protein, Vip1Ac (66 kDa) and Vip 2Ac (45 kDa). Both the Bacillus sphaericus strains showed a 35 kDa band that was similiar to a previously reported vegetative protein, the Mtx2 protein. Bs 2 also contains a 37 kDa band, similar to another vegetative protein, the Mtx 3 protein. With the exception of Bt 17 and Bt 21, vegetative proteins from all Bacillus thuringiensis and Bacillus sphaericus strains were highly haemolytic to human erythrocytes, causing more than 75% haemolysis at the highest concentration of 200 microg/ml. High haemolytic activity was associated with high cytotoxic activity with most of the haemolytic strains being indiscriminately cytotoxic to both CEM-SS (human T lymphoblastoid) and HeLa (human uterus cervical cancer) cell lines. Interestingly, the less haemolytic vegetative proteins from Bt 17 and Bt 21 demonstrated cytotoxic activity comparable to that of the highly haemolytic vegetative proteins. Bt 21 displayed toxicity towards both cell lines while Bt 17 was more toxic towards CEM-SS cells. Bioassay against Aedes aegypti and Culex quinquefasciatus larvae revealed that vegetative proteins from the Bacillus thuringiensis strains had activity against both species of larvae but vegetative proteins from Bacillus sphaericus were weakly larvicidal towards Cx. quinquefasciatus only.

Matched MeSH terms: Bacillus thuringiensis/isolation & purification; Bacillus thuringiensis/metabolism*
Synthesis, spectral analysis and antibacterial activity of some novel 5-substituted-2-((6-bromo-3,4-methylenedioxybenzyl)thio)-1,3,4-oxadiazole derivatives

Rehman A, Siddiqa A, Abbasi MA, Siddiqui SZ, Khan SG, Rasool S, et al.

Pak J Pharm Sci, 2018 Sep;31(5):1783-1790.
PMID: 30150171

A number of novel 5-substituted-2-((6-bromo-3,4-methylenedioxybenzyl)thio)-1,3,4-Oxadiazole derivatives (6a-l) have been synthesized to evaluate their antibacterial activity. Using aryl/aralkyl carboxylic acids (1a-l) as precursors, 5-substituted-1,3,4-Oxadiazol-2-thiols (4a-l) were yielded in good amounts. The derivatives, 4a-l, were subjected to electrophilic substitution reaction on stirring with 6-bromo-3,4-methylenedioxybenzyl chloride (5) in DMF to synthesize the required compounds. All the synthesized molecules were well characterized by IR, 1H-NMR, 13C-NMR and EIMS spectral data and evaluated for antibacterial activity against some bacterial strains of Gram-bacteria. The molecule, 6d, demonstrated the best activity among all the synthesized molecules exhibiting weak to moderate inhibition potential.

Matched MeSH terms: Bacillus subtilis/drug effects; Bacillus subtilis/growth & development
Direct recovery of Bacillus subtilis xylanase from fermentation broth with an alcohol/salt aqueous biphasic system

Ng HS, Chai CXY, Chow YH, Loh WLC, Yim HS, Tan JS, et al.

J Biosci Bioeng, 2018 May;125(5):585-589.
PMID: 29339003 DOI: 10.1016/j.jbiosc.2017.12.010

Xylanase enzyme degrades linear polysaccharide β-1,4 xylan and the hemicellulose of the plant cell wall. There is a growing demand in finding a cost-effective alternative for industrial scale production of xylanase with high purity for pharmaceutical applications. In this study, an alcohol/salt aqueous biphasic system (ABS) was adopted to recover xylanase from the Bacillus subtilis fermentation broth. The effects of several ABS parameters such as types and concentrations of alcohols and salts (i.e., sulphate, phosphate, and citrate), amount of crude loading and pH of the system on the recovery of xylanase were investigated. Partition coefficient of xylanase (KE), selectivity (S) and yield (YT) of xylanase in top phase of the ABS were measured. Highest KE (6.58 ± 0.05) and selectivity (4.84 ± 0.33) were recorded in an ABS of pH 8 composed of 26% (w/w) 1-propanol, 18% (w/w) ammonium sulphate. High YT of 71.88% ± 0.15 and a purification fold (PFT) of 5.74 ± 0.33 were recorded with this optimum recovery of xylanase using alcohol/salt ABS. The purity of xylanase recovered was then qualitatively verified with sodium dodecyl sulphate (SDS) gel electrophoresis. The SDS profile revealed the purified xylanase was successfully obtained in the top phase of the one-step 1-propanol/sulphate ABS with a distinct single band.

Matched MeSH terms: Bacillus subtilis/enzymology*; Bacillus subtilis/metabolism
Fulltext Investigation on the antimicrobial activities of gingers (Etlingera coccinea (Blume) S.Sakai & Nagam and Etlingera sessilanthera R.M.Sm.) endemic to Borneo

Daniel-Jambun D, Dwiyanto J, Lim YY, Tan JBL, Muhamad A, Yap SW, et al.

J Appl Microbiol, 2017 Oct;123(4):810-818.
PMID: 28708293 DOI: 10.1111/jam.13536

AIMS: To investigate the antimicrobial properties of Etlingera coccinea and Etlingera sessilanthera and to isolate and identify the antimicrobial compounds.
METHODS AND RESULTS: Extracts were obtained via sequential solvent extraction method using hexane, dichloromethane, ethyl acetate, methanol and water. Antimicrobial activity testing was done using broth microdilution assay against 17 strains of bacteria. The leaf hexane extract of E. coccinea and rhizome hexane extract of E. sessilanthera showed best antimicrobial activities, with minimum inhibitory concentration (MIC) values ranging from 0·016 to 1 mg ml-1 against Gram-positive bacteria. From these active extracts, two antimicrobials were isolated and identified as trans-2-dodecenal and 8(17),12-labdadiene-15,16-dial with MIC values ranging from 4 to 8 μg ml-1 against Bacillus cereus, Bacillus subtilis and Staphylococcus aureus.
CONCLUSION: Etlingera coccinea and E. sessilanthera demonstrated good antimicrobial activities against clinically relevant bacteria strains. The antimicrobial compounds isolated showed low MIC values, hence suggesting their potential use as antimicrobial agents.
SIGNIFICANCE AND IMPACT OF THE STUDY: This study is the first to identify the potent antimicrobials from these gingers. The antimicrobials isolated could potentially be developed further for use in treatment of bacterial infections. Also, this study warrants further research into other Etlingera species in search for more antimicrobial compounds.

Matched MeSH terms: Bacillus cereus/drug effects; Bacillus cereus/growth & development
Fulltext Role of Bacillus cereus in Improving the Growth and Phytoextractability of Brassica nigra (L.) K. Koch in Chromium Contaminated Soil

Akhtar N, Ilyas N, Yasmin H, Sayyed RZ, Hasnain Z, A Elsayed E, et al.

Molecules, 2021 Mar 12;26(6).
PMID: 33809305 DOI: 10.3390/molecules26061569

Plant growth-promoting rhizobacteria (PGPR) mediate heavy metal tolerance and improve phytoextraction potential in plants. The present research was conducted to find the potential of bacterial strains in improving the growth and phytoextraction abilities of Brassica nigra (L.) K. Koch. in chromium contaminated soil. In this study, a total of 15 bacterial strains were isolated from heavy metal polluted soil and were screened for their heavy metal tolerance and plant growth promotion potential. The most efficient strain was identified by 16S rRNA gene sequencing and was identified as Bacillus cereus. The isolate also showed the potential to solubilize phosphate and synthesize siderophore, phytohormones (indole acetic acid, cytokinin, and abscisic acid), and osmolyte (proline and sugar) in chromium (Cr+3) supplemented medium. The results of the present study showed that chromium stress has negative effects on seed germination and plant growth in B. nigra while inoculation of B. cereus improved plant growth and reduced chromium toxicity. The increase in seed germination percentage, shoot length, and root length was 28.07%, 35.86%, 19.11% while the fresh and dry biomass of the plant increased by 48.00% and 62.16%, respectively, as compared to the uninoculated/control plants. The photosynthetic pigments were also improved by bacterial inoculation as compared to untreated stress-exposed plants, i.e., increase in chlorophyll a, chlorophyll b, chlorophyll a + b, and carotenoid was d 25.94%, 10.65%, 20.35%, and 44.30%, respectively. Bacterial inoculation also resulted in osmotic adjustment (proline 8.76% and sugar 28.71%) and maintained the membrane stability (51.39%) which was also indicated by reduced malondialdehyde content (59.53% decrease). The antioxidant enzyme activities were also improved to 35.90% (superoxide dismutase), 59.61% (peroxide), and 33.33% (catalase) in inoculated stress-exposed plants as compared to the control plants. B. cereus inoculation also improved the uptake, bioaccumulation, and translocation of Cr in the plant. Data showed that B. cereus also increased Cr content in the root (2.71-fold) and shoot (4.01-fold), its bioaccumulation (2.71-fold in root and 4.03-fold in the shoot) and translocation (40%) was also high in B. nigra. The data revealed that B. cereus is a multifarious PGPR that efficiently tolerates heavy metal ions (Cr+3) and it can be used to enhance the growth and phytoextraction potential of B. nigra in heavy metal contaminated soil.

Matched MeSH terms: Bacillus cereus/genetics; Bacillus cereus/physiology*
Fulltext Biosorption Potential of Bacillus salmalaya Strain 139SI for Removal of Cr(VI) from Aqueous Solution

Dadrasnia A, Chuan Wei KS, Shahsavari N, Azirun MS, Ismail S

Int J Environ Res Public Health, 2015 Dec;12(12):15321-38.
PMID: 26633454 DOI: 10.3390/ijerph121214985

The present study investigated the biosorption capacity of live and dead cells of a novel Bacillus strain for chromium. The optimum biosorption condition was evaluated in various analytical parameters, including initial concentration of chromium, pH, and contact time. The Langmuir isotherm model showed an enhanced fit to the equilibrium data. Live and dead biomasses followed the monolayer biosorption of the active surface sites. The maximum biosorption capacity was 20.35 mg/g at 25 °C, with pH 3 and contact time of 50 min. Strain 139SI was an excellent host to the hexavalent chromium. The biosorption kinetics of chromium in the dead and live cells of Bacillus salmalaya (B. salmalaya) 139SI followed the pseudo second-order mechanism. Scanning electron microscopy and fourier transform infrared indicated significant influence of the dead cells on the biosorption of chromium based on cell morphological changes. Approximately 92% and 70% desorption efficiencies were achieved using dead and live cells, respectively. These findings demonstrated the high sorption capacity of dead biomasses of B. salmalaya 139SI in the biosorption process. Thermodynamic evaluation (ΔG⁰, ΔH⁰, and ΔS⁰) indicated that the mechanism of Cr(VI) adsorption is endothermic; that is, chemisorption. Results indicated that chromium accumulation occurred in the cell wall of B. salmalaya 139SI rather than intracellular accumulation.

Matched MeSH terms: Bacillus
Fulltext Changes in physicochemical characteristics of ozone-treated raw white rice

Shah NN, Rahman RA, Hashim DM

J Food Sci Technol, 2015 Mar;52(3):1525-33.
PMID: 25745221 DOI: 10.1007/s13197-013-1111-y

Ozone dose from 0.1 to 0.4 ppm has been proven to be effective in lowering Bacillus cereus count in uncooked and cooked rice. However, it induces physicochemical changes in raw white rice. Physicochemical tests were done to see the effect of ozone treatment towards moisture content, pH, color, hardness of uncooked rice, adhesiveness and hardness of cooked rice, cooking quality and total solids. Results have shown that moisture content, adhesiveness and hardness of cooked rice and uncooked rice have not undergone any significant changes (P > 0.05) in comparison with controlled rice sample. Meanwhile, color (L* and b* value), pH, total solids and cooking quality results have shown significant changes (P

Matched MeSH terms: Bacillus cereus
Fulltext Selection and identification of non-pathogenic bacteria isolated from fermented pickles with antagonistic properties against two shrimp pathogens

Zokaeifar H, Balcázar JL, Kamarudin MS, Sijam K, Arshad A, Saad CR

J Antibiot (Tokyo), 2012 Jun;65(6):289-94.
PMID: 22491136 DOI: 10.1038/ja.2012.17

In this study, potential probiotic strains were isolated from fermented pickles based on antagonistic activity against two shrimp pathogens (Vibrio harveyi and Vibrio parahaemolyticus). Two strains L10 and G1 were identified by biochemical tests, followed by16S ribosomal RNA gene sequence analysis as Bacillus subtilis, and characterized by PCR amplification of repetitive bacterial DNA elements (Rep-PCR). Subsequently, B. subtilis L10 and G1 strains were tested for antibacterial activity under different physical conditions, including culture medium, salinity, pH and temperature using the agar well diffusion assay. Among the different culture media, LB broth was the most suitable medium for antibacterial production. Both strains showed the highest level of antibacterial activity against two pathogens at 30 °C and 1.0% NaCl. Under the pH conditions, strain G1 showed the greatest activity against V. harveyi at pH 7.3-8.0 and against V. parahaemolyticus at pH 6.0-8.0, whereas strain L10 showed the greatest activity against two pathogens at pH 7.3. The cell-free supernatants of both strains were treated with four different enzymes in order to characterize the antibacterial substances against V. harveyi. The result showed considerable reduction of antibacterial activity for both strains, indicating the proteinaceous nature of the antibacterial substances. A wide range of tolerance to NaCl, pH and temperature was also recorded for both strains. In addition, both strains showed no virulence effect in juvenile shrimp Litopenaeus vannamei. On the basis of these results and safety of strains to L. vannamei, they may be considered for future challenge experiments in shrimp as a very promising alternative to the use of antibiotics.

Matched MeSH terms: Bacillus subtilis/classification*; Bacillus subtilis/genetics; Bacillus subtilis/isolation & purification
Rapid degradation of N-3-oxo-acylhomoserine lactones by a Bacillus cereus isolate from Malaysian rainforest soil

Chan KG, Wong CS, Yin WF, Sam CK, Koh CL

Antonie Van Leeuwenhoek, 2010 Oct;98(3):299-305.
PMID: 20376561 DOI: 10.1007/s10482-010-9438-0

A bacterial strain, KM1S, was isolated from a Malaysian rainforest soil sample by using a defined enrichment medium that specifically facilitates selection of quorum quenching bacteria. KM1S was clustered closely to Bacillus cereus by 16S ribosomal DNA sequence analysis. It degraded N-3-oxo-hexanoyl homoserine lactone and N-3-oxo-octanoyl homoserine lactone in vitro rapidly at 4.98 and 6.56 microg AHL h(-1) per 10(9) CFU/ml, respectively, as determined by the Rapid Resolution Liquid Chromatography. The aiiA homologue, encoding an autoinducer inactivation enzyme catalyzing the degradation of N-acylhomoserine lactones, of KM1S was amplified and cloned. Sequence analysis indicated the presence of the motif (106)HXDH-59 amino acids-H(169)-21 amino acids-D(191) for N-acylhomoserine lactone lactonases.

Matched MeSH terms: Bacillus cereus/genetics; Bacillus cereus/isolation & purification; Bacillus cereus/metabolism*
Direct recovery of cyclodextringlycosyltransferase from Bacillus cereus using aqueous two-phase flotation

Lin YK, Show PL, Yap YJ, Tan CP, Ng EP, Ariff AB, et al.

J Biosci Bioeng, 2015 Dec;120(6):684-9.
PMID: 26111602 DOI: 10.1016/j.jbiosc.2015.04.013

Purification of cyclodextrin glycosyl transferase (CGTase) from Bacillus cereus using polyethylene glycol (PEG)-potassium phosphates aqueous two-phase flotation (ATPF) system was studied in this paper. The effects of varying PEG molecular weight, tie-line length (TLL) value, volume ratio (VR), pH value, crude concentration and gas nitrogen flotation time were investigated. The optimal condition for purification of CGTase was attained at 18.0% (w/w) PEG 8000, 7.0% (w/w) potassium phosphates, VR of 3.0, 20% (w/w) crude load at pH 7, and 80 min nitrogen flotation time at a flow rate of 5 L/min. With this optimal condition, purification factor (PFT) of 21.8 and a yield (YT) of 97.1% were attained. CGTase was successfully purified in a single downstream processing step using the ATPF.

Matched MeSH terms: Bacillus cereus
Characterization and utilization of pulp and paper mill sludge digesting thermophilic bacteria in composting process

Le Van Thien, Ngo Thi Tuong Chau, Pham Thi Ngoc Lan, Hiroyuki Futamata

Sains Malaysiana, 2018;47:1051-1060.

Pulp and paper mill sludge (PPMS) was found to be poorly colonised with thermophilic microorganisms. However,
evidence to support the need for inoculation to facilitate PPMS composting has only been demonstrated in one instance.
In this study, we aimed to: screen and identify PPMS digesting thermophilic bacterial strains; investigate effects of the
mixture of selected thermophilic bacterial strains on PPMS digestion; and utilize this mixture as start inoculum in PPMS
composting and assess the quality of compost product. The results showed that eleven thermophilic bacterial strains were
isolated from Bai Bang PPMS by the enrichment culture method. Among these, three strains which reflected high growth
rates on the plates of Minimal Media Agar supplemented with Bai Bang PPMS and showed hydrolytic and ligninolytic
activities on the agar plates containing appropriate inductive substrates were selected. Based on the morphological,
biochemical characteristics and 16S rRNA gene sequencing, they were identified as Bacillus subtilis. The inoculation
with the mixture of selected strains enhanced remarkably Bai Bang PPMS digestion. The dry weight decrease, volatile
suspended solids removal, dehydrogenase and protease activities in the inoculated sludge were 2.1-, 1.5-, 1.3- and 1.2-
fold higher, respectively, compared to the non-inoculated sludge. The assessment of compost quality based on stability
using the alkaline trap method and maturity using the germination and root elongation test showed that the inoculated
compost was stable and mature while the non-inoculated compost was unstable and immature. These thermophilic
bacterial strains therefore have great potential for Bai Bang PPMS composting.

Matched MeSH terms: Bacillus subtilis
Structural approaches for the DNA binding motifs prediction in Bacillus thuringiensis sigma-E transcription factor (σETF)

Lim YY, Lim TS, Choong YS

J Mol Model, 2019 Sep 05;25(10):301.
PMID: 31486892 DOI: 10.1007/s00894-019-4192-3

The sigma-E transcription factor (σETF) can be found in most of the bacteria cells including Bacillus thuringiensis. However, the cellular regulatory mechanisms of these transcription factors in the mass production of δ-endotoxins during sporulation stage are yet to be revealed. In addition, the recognition of DNA towards σETF DNA binding motifs that led to the transcription activities is also being poorly studied. Therefore, this work studied the possible DNA binding motifs of σETF by utilising in silico approaches. The structure of σETF was first built via three different computational methods. A cognate DNA sequence was then docked to the predicted σETF DNA-binding motifs. The binding free energy calculated using molecular mechanics/Poisson-Boltzmann surface area (MM-PBSA) for triplicate 50 ns simulation of σETF-DNA complex revealed favourable binding energy of DNA to σETF (average ∆Gbind = -34.57 kcal/mol) mainly driven by non-polar interactions. This study revealed that σETF LYS131, ARG133, PHE138, TRP146, ARG222, LYS225 and ARG226 are most likely the key residues upon the binding and recognition of DNA prior to transcription actives. Since determination of genome-regulating protein which recognises specific DNA sequence is important to discriminate between the proteins preferences for different genes, this study might provide some understanding on the possible σETF-DNA recognition prior to transcription initiated for the δ-endotoxins production.

Matched MeSH terms: Bacillus thuringiensis
Indoor thermal fogging against vector mosquitoes with two Bacillus thuringiensis israelensis formulations, Vectobac ABG 6511 water-dispersible granules and Vectobac 12AS liquid

Yap HH, Lee YW, Zairi J

J Am Mosq Control Assoc, 2002 Mar;18(1):52-6.
PMID: 11998931

Bioefficacy of thermal fogging application of 2 Bacillus thuringiensis israelensis formulations, Vectobac ABG 6511 water-dispersible granules (3,000 international toxic unit [ITU]/mg) and Vectobac 12AS liquid (1,200 ITU/mg), was assessed for larvicidal activities against Aedes aegypti, Aedes albopictus, Anopheles dirus, and Culex quinquefasciatus. Portable Agrofog AF35 sprayers were used to apply the 2 formulations indoors in residential premises on Penang Island, Malaysia. Vectobac ABG 6511 showed good larvicidal effect against all 4 mosquito species at 3 of the higher doses tested (2.91 x 10(9), 1.45 x 10(9), and 0.71 x 10(9) ITU/ha), with more than 96% mortality at 48 h after spraying. As a comparative formulation, Vectobac 12AS also showed good larvicidal activity against all 4 mosquito species at 2 of the higher doses tested (2.87 x 10(9) and 1.46 x 10(9) ITU/ha), with more than 92.5% mortality at 48 h after spraying. Larvae of An. dirus were significantly more susceptible to both water-based Vectobac formulations when compared to the other 3 mosquito species. Both microbial formulations showed better efficacy at higher doses. However, even at the lowest dose tested, Vectobac ABG 6511 and Vectobac 12AS (both at 0.36 x 10(9) ITU/ha) showed larvicidal properties, with more than 66% mortality at 48 h after spraying. Overall, for this bacterial agent, the water-dispersible granule formulation has better prospects than the liquid formulation for the control of larvae of vector mosquitoes.

Matched MeSH terms: Bacillus thuringiensis
Fulltext Utilization of acid pre-treated coconut dregs as a substrate for production of detergent compatible lipase by Bacillus stratosphericus

Mohd Zin NB, Mohamad Yusof B, Oslan SN, Wasoh H, Tan JS, Ariff AB, et al.

AMB Express, 2017 Dec;7(1):131.
PMID: 28651380 DOI: 10.1186/s13568-017-0433-y

In recent years, many efforts have been directed to explore the methods to reduce the production costs of industrial lipase by improving the yield and the use of low-cost agricultural wastes. Coconut dregs, which is a lignocellulosic by-product from coconut oil and milk processing plants, is rich in cellulose (36%) and crude fat (9%). A newly isolated Bacillus stratosphericus has been demonstrated to perform cellulose hydrolysis on coconut dregs producing fermentable sugars. The highest extracellular lipase activity of 140 U/mL has been achieved in submerged fermentation with acid pre-treated coconut dregs. The lipase was found to be active over a wide range of temperatures and pHs. The activity of lipase can be generally increased by the presence of detergent ingredients such as Tween-80, cetyltrimethylammonium bromide, hydrogen peroxide and phosphate per sulphate. The great compatibility of lipase in commercial detergents has also underlined its potential as an additive ingredient in biodetergent formulations.

Matched MeSH terms: Bacillus
A new organic solvent tolerant protease from Bacillus pumilus 115b

Rahman RN, Mahamad S, Salleh AB, Basri M

J Ind Microbiol Biotechnol, 2007 Jul;34(7):509-17.
PMID: 17492323

Five out of the nine benzene-toulene-ethylbenzene-xylene (BTEX) tolerant bacteria that demonstrated high protease activity on skim milk agar were isolated. Among them, isolate 115b identified as Bacillus pumilus exhibited the highest protease production. The protease produced was stable in 25% (v/v) benzene and toluene and it was activated 1.7 and 2.5- fold by n-dodecane and n-tetradecane, respectively. The gene encoding the organic solvent tolerant protease was cloned and its nucleotide sequence determined. Sequence analysis revealed an open reading frame (ORF) of 1,149 bp that encoded a polypeptide of 383 amino acid residues. The polypeptide composed of 29 residues of signal peptide, a propeptide of 79 residues and a mature protein of 275 amino acids with a calculated molecular mass of 27,846 Da. This is the only report available to date on organic solvent tolerant protease from B. pumilus.

Matched MeSH terms: Bacillus/classification; Bacillus/enzymology*; Bacillus/genetics
Fulltext A Host-Vector System for the Expression of a Thermostable Bacterial Lipase in a Locally Isolated Meyerozyma guilliermondii SMB

Salleh AB, Baharuddin SM, Rahman RNZRA, Leow TC, Basri M, Oslan SN

Microorganisms, 2020 Nov 06;8(11).
PMID: 33171893 DOI: 10.3390/microorganisms8111738

Screening for a new yeast as an alternative host is expected to solve the limitations in the present yeast expression system. A yeast sample which was isolated from the traditional food starter 'ragi' from Malaysia was identified to contain Meyerozyma guilliermondii strain SMB. This yeast-like fungus strain SMB was characterized to assess its suitability as an expression host. Lipase activity was absent in this host (when assayed at 30 °C and 70 °C) and Hygromycin B (50 μg/mL) was found to be its best selection marker. Then, the hyg gene (Hygromycin B) was used to replace the sh ble gene (Zeocin) expression cassette in a Komagataella phaffii expression vector (designated as pFLDhα). A gene encoding the mature thermostable lipase from Bacillus sp. L2 was cloned into pFLDhα, followed by transformation into strain SMB. The optimal expression of L2 lipase was achieved using YPTM (Yeast Extract-Peptone-Tryptic-Methanol) medium after 48 h with 0.5% (v/v) methanol induction, which was 3 times faster than another K. phaffii expression system. In conclusion, a new host-vector system was established as a platform to express L2 lipase under the regulation of PFLD1. It could also be promising to express other recombinant proteins without inducers.

Matched MeSH terms: Bacillus

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