Brachionus plicatilis is used to feed fish and crustacean larvae in the aquaculture industry. It is well established that the type of microalgae may influence rotifer production. This experiment was conducted to determine the effect of five different locally available microalgae species at Fisheries Research Institute (FRI), Kampung Pulau Sayak, Kedah, Malaysia on the instantaneous growth rate (μ) of rotifer. Nannochloris sp., Tetraselmis sp., Isochrysis sp., Chlorella sp., and Nannochloropsis sp. were used as feed at different algae densities (0.1, 0.3, 0.7 and 1.5 × 106 cells/ml) and culture volumes (20, 70 and 210 ml). At algae densities ranging from 0.3 to 1.5 × 106 cells/ml, an average μ value of more than 0.90 per day were recorded for all algae species. However, at density of 0.1 × 106 cells/ml, only Tetraselmis sp. resulted in the significantly highest μ value compared with others (p < 0.05). In terms of volume, smaller culture volume of Tetraselmis sp. (20 ml) showed significantly higher μ compared with higher volume (70 and 210 ml cultures).
Nowadays, there is a rising interest towards consuming health beneficial food products. Bread-as one of the most popular food products-could be improved to 'healthy bread' by addition of ingredients high in protein, dietary fiber and low in calorie. Incorporating Jackfruit rind powder (JRP) as a by-product rich in dietary fiber in bread, could not only provide health beneficial bread products, but also lead to develop an environmental friendly technology by solving the problem of waste disposal of residues. In this study, addition of jackfruit rind powder (JRP) as a high dietary fiber and functional ingredient in bread was examined. The results showed that incorporation of JRP in bread improved functional properties of flour such as Oil Holding Capacity (OHC), Water Holding Capacity (WHC) and pasting properties. Addition of 5%, 10% and 15% of JRP in wheat flour caused significantly (p < 0.05) higher insoluble, soluble and total dietary fiber in flour and bread products. Results from proximate composition indicated that all breads substituted with JRP, contained significantly (p < 0.05) higher fiber, moisture and fat. Obtained results confirmed that the JRP has great potential in development of functional foods especially functional bread products.
The effect of low pH on the tactile sense of Macrobrachium rosenbergii postlarvae was determined in the laboratory by means of two behavioural assays: shelter (netting) occupancy and jumping response to touch stimuli (taps) by a glass micropipette. The postlarvae were acclimated to pH 4, pH 5, pH 6 and pH 7.5 (control) in 45 L aquaria 5-7 d before the experiments. Shelter occupancy decreased with pH and was significantly lower at pH 4 and pH 5 than at pH 6 and in the control. The jumping response instantly followed a tap 93-98% of the time in the control, pH 6 and pH 5 treatments. However, the postlarvae showed significantly lower jumping response (65%) at pH 4, indicating an impaired tactile sense. Low pH 4-5 probably degrades the chitin of the sensory setae and inhibits the surface mechanoreceptors of the prawn postlarvae.
Spheroids have been shown to recapitulate the tumour in vivo with properties
such as the tumour microenvironment, concentration gradients, and tumour phenotype. As
such, it can serve as a platform for determining the growth and invasion behaviour pattern
of the cancer cells as well as be utilised for drug sensitivity assays; capable of exhibiting
results that are closer to what is observed in vivo compared to two-dimensional (2D) cell
culture assays. This study focused on establishing a three-dimensional (3D) cell culture
model using the Nasopharyngeal Carcinoma (NPC) cell line, HK1 and analysing its growth
and invasion phenotypes. The spheroids will also serve as a model to elucidate their
sensitivity to the chemotherapeutic drug, Flavopiridol. The liquid overlay method was
employed to generate the spheroids which was embedded in bovine collagen I matrix for
growth and invasion phenotypes observation. The HK1 cells formed compact spheroids
within 72 hours. Our observation from the 3 days experiments revealed that the spheroids
gradually grew and invaded into the collagen matrix, showing that the HK1 spheroids are
capable of growth and invasion. Progressing from these experiments, the HK1 spheroids
were employed to perform a drug sensitivity assay using the chemotherapeutic drug,
Flavopiridol. The drug had a dose-dependent inhibition on spheroid growth and invasion.
Throughout the cryopreservation process, plants were exposed to a series of
abiotic stresses such as desiccation and osmotic pressure due to highly concentrated
vitrification solution. Abiotic stress stimulates the production of reactive oxygen species
(ROS) which include hydrogen peroxide, superoxide radicals, and singlet oxygen. Higher
production of ROS may lead to oxidative stress which contributes to the major injuries in
cryopreserved explants. Antioxidant enzymes in plant such as ascorbate peroxidase
(APX) can protect plants from cell damage by scavenging the free radicals. This study was
determined based on APX enzyme activity of Aranda Broga Blue orchid’s protocorm-like
bodies (PLBs) in response to PVS2 (Plant Vitrification Solution 2) cryopreservation
treatments at different stages. PLBs that were precultured at 0.25 M sucrose for 3 days
were subjected to vitrification cryopreservation method. Results obtained showed that the
highest APX activity was achieved at PVS2 cryoprotectant treatment prior liquid nitrogen
(LN) storage. This phenomenon indicating that accumulation of osmotic and dehydrating
stress throughout the cryopreservation treatment resulted in oxidative burst which in turn
leads to higher APX activity in order to control the excess production of ROS. To
conclude, PVS2 treatment was revealed as the most detrimental step throughout
cryopreservation treatment. Thus, this research also suggested that exogenous
antioxidant such as ascorbic acid can be added throughout cryopreservation procedure
especially at PVS2 treatment in the future experiments to aid in regrowth of cryopreserved
explants by reducing oxidative stress.
We report on the cloning of the lipase gene from Bacillus licheniformis IBRLCHS2
and the expression of the recombinant lipase. DNA sequencing analysis of the
cloned lipase gene showed that it shares 99% identity with the lipase gene from
B. licheniformis ATCC 14580 and belongs to subfamily 1.4 of true lipases based on amino
acid sequence alignment of various Bacillus lipases. The 612 bp lipase gene was then
cloned into the pET-15b(+) expression vector and the construct was transformed into
E. coli BL21 (DE3) for bulk expression of the lipase. Expression was analysed by SDSPAGE
where the lipase was found to have a molecular weight of about 23 kDa.
A lipase producer psychrophilic microorganism isolated from Arctic sample was
studied. The genomic DNA of the isolate was extracted using modified CTAB method.
Identification of the isolate by morphological and 16S rRNA sequence analysis revealed
that the isolate is closely related to Arthrobacter gangotriensis (97% similarity).
A. gangotriensis was determined as positive lipase producer based on the plate screening
using specific and sensitive plate assay of Rhodamine B. The PCR result using
Arthrobacter sp.’s full lipase gene sequence as the template primers emphasised a
possible lipase gene at 900 bp band size. The gene is further cloned in a suitable vector
system for expression of lipase.
A survey on termite species composition was conducted in Samunsam Wildlife Sanctuary, Sarawak in February 2015. Overall 19 species of termite belonging to 13 genera and 8 subfamilies was found in the sanctuary. It was recorded the subfamily of Termitinae had the highest number of species (6 species, equal to 31.58% of total species), followed by Nasutermitinae (3 species, 15.79%), Macrotermitinae, Amitermitinae, Rhinotermitinae, Coptotermitinae, (2 species, 10.53% respectively), and Heterotermitinae, Termitogetoninae (1 species, 5.26% respectively). Since this rapid survey is the first termite assemblage representation in Samunsam Wildlife Sanctuary, the preliminary result may serve as the baseline data for termite composition in the area. Therefore, a whole coverage for the area within this sanctuary would definitely increase the number of termite species found in the sanctuary.
To understand the effects of fish predator’s kairomones on Aedes mosquitoes’
oviposition, we established an experiment using gravid Aedes females. Kairomones
concentrations were established using Hampala macrolepidota. One individual fish was
placed inside containers with varying water levels (1 L, 5 L, and 10 L of water). The fish
were kept in the containers for 24 hours and were removed immediately at the start of
each trial in order to have the kairomones remnants. Twenty gravid adult females of
Aedes aegypti and Aedes albopictus were allowed to lay eggs on oviposition site with
various treatments: (1) control without any kairomones; (2) kairomone remnant in 1 L of
water; (3) kairomone remnant in 5 L of water; and (4) kairomone remnant in 10 L of water.
There are significant differences between the numbers of eggs laid by both Aedes species
for each different treatment (F = 9.131, df = 16, p
Citrus canker caused by Xanthomonas citri subsp. citri is a disease affecting the yield and fruit quality of lime (Citrus aurantiifolia). This research investigated endophytic bacteria obtained from six healthy Citrus spp. to inhibit the pathogen and to control citrus canker on lime plants. Numbers of the endophytic bacteria isolated from C. aurantifolia, C. hystrix, C. maxima, C. nobilis, C. reticulata and C. sinensis were 28, 25, 29, 42, 12 and 34 isolates, respectively. The selected endophytic bacteria that were effective against X. citri subsp. citri were Bacillus amyloliquefaciens LE109, B. subtilis LE24 and B. tequilensis PO80. The optimum culture medium for an antagonistic effect on the pathogen in B. amyloliquefaciens LE109 and B. tequilensis PO80 was yeast extract peptone dextrose broth, and in B. subtilis LE24 was modified soluble starch broth. To control citrus canker in lime, young expanded leaves of lime plants were aseptically punctured and inoculated with 30 μl of bacterial suspension of the pathogen (108 CFU/ml in 0.85% NaCl) per punctured location. After the pathogenic inoculation for 24 h, the leaves were then inoculated with 30 μl of the selected endophytic bacteria (108 CFU/ml in 0.85% NaCl), and treated with 30 μl of the culture media containing bioactive compounds produced by the selected endophytic bacteria. The leaves inoculated with cell suspensions of B. amyloliquefaciens LE109 or B. subtilis LE24 could completely control citrus canker. However, the leaves inoculated with B. tequilensis PO80 displayed 10% disease incidence. Additionally, the leaves treated with the crude bioactive compounds of B. amyloliquefaciens LE109 or B. subtilis LE24 could completely control citrus canker. Notably, the leaves treated with the crude bioactive compounds of B. tequilensis PO80 displayed 5% disease incidence. The results of this study showed that the Bacillus strains play important roles in the biocontrol of citrus canker in lime.
A number of countries, including developed countries, still have typhoid fever as a major problem resulting in frequent outbreaks. The importance of controlling spread of typhoid fever is well known and necessitates periodic studies to delineate epidemiological relationships. Although phage typing remains to be the preferred conventional method for characterisation of typhoid bacilli, it is of limited use due to prevalence of few predominant phage types in the country like India. Therefore, an effort has been made to assess three molecular methods [Outer Membrane Protein (OMP) Profiling, Random Amplification of Polymorphic DNA (RAPD) and Pulsed Field Gel Electrophoresis (PFGE)] for typing of Salmonella enterica serovar Typhi. 128 Salmonella enterica serovar Typhi isolates were identified using biotyping and serotyping followed by antimicrobial susceptibility testing. These isolates were further subjected to OMP analysis, RAPD and PFGE. PFGE (114 unique clusters) was found to be the most discriminatory method followed by RAPD (94 unique clusters) and OMP profiling (50 unique clusters). Multidrug resistant strains were well discriminated by all three methods used in the study. PFGE still remains the most preferred method for detailed epidemiological investigations. However, random amplification of polymorphic DNA and outer membrane protein profiling can also be considered for molecular discrimination of the isolates in the laboratories lacking high-end facilities.
This study examined the tunneling activity and the behaviour of two subterranean termites, Globitermes sulphurues and Coptotermes gestroi treated with four plant extracts, namely Pyllanthus niruri, Azadirachta indica, Leucaena leucocephala and Andrographis paniculata. All plants were extracted with three different solvents (methanol, hexane and water) and were diluted into three concentrations (500, 5,000 and 10,000 ppm). A group of 50 workers and 2 soldiers were tested and observed daily during the exposure in order to determine their survivorship and behaviour. Both sections were scored to determine their tunneling activities after seven days. There was a significant difference of tunneling activities of C. gestroi on sand treated with plant extracts (X2(2) = 31.790, p < 0.0001) with a mean rank of 8.50 for methanolic extracts and 32.50 for both hexane and water extracts. Meanwhile, no significant difference was observed on tunneling activity of G. sulphureus on treated sand (X2(2) = 2.200, p = 0.333) with a mean rank of 20.72 for methanolic extracts, 26.31 for water extracts and 26.47 for hexane extracts. Results showed that plants extracted with methanol demonstrated strong repellent properties with 0 tunneling activity on the treated sand and low survivorship of both termites. Moreover, both termites did not survive (0%) when they were treated with methanolic extracts at 10,000 ppm. They also displayed a different behaviour post-exposure such as avoidance, gradually losing the ability to walk and low feeding consumption. These results indicate that there is a strong termiticidal activity of plants extracted with methanol against C. gestroi and G. sulphureus.
Ficus plants are commonly planted as ornamentals along roadsides in Malaysia. In 2010, Ficus plants in Kuala Terengganu were found to be attacked by a moth, identified as Trilocha varians. The larvae of this moth fed on Ficus leaves causing up to 100% defoliation. This study was conducted to determine the life cycle of T. varians under two different environmental temperatures and to control this pest using two different insecticides. Our findings showed that there were significant differences in the time taken for eggs to hatch and larval and pupation period between low and high environmental temperatures. Results also showed that fipronil had lower LT50 and LT95 than malathion. This study provides new information on the life history of T. varians under two different conditions and the efficiency in controlling T. varians larvae using insecticides. The results of this study are important for future management in controlling T. varians population especially in Kuala Terengganu, Malaysia.
Taxonomic study on the composition of epiphytic algae living on submerged leaf and root tissues of macrophyte Eichhornia crassipes (Mart.) Solms-Loubach, found at Laguna de Bay, Philippines was conducted. In total, 21 algal taxa were identified: seven Cyanophyceae, six Euglenophyceae, five Chlorophyceae, two Trebouxiophyceae and one Klebsormidiophyceae. Of these taxa, the occurrence of two rare cyanobacteria, Pseudanabaena minima (G.S. An) Anagnostidis and Synechococcus nidulans (Pringsheim) Komárek are reported for the first time in the Philippines. Two species are also reported here for the first time in the Philippines based on current taxonomic nomenclature and these are Pseudopediastrum boryanum (Turpin) E. Hegewald, Phormidium granulatum (Gardner) Anagnostidis which were based on the former names of Pediastrum boryanum (Turpin) Meneghini and Oscillatoria granulata Gardner, respectively. These taxonomic records are considered important basal information in enriching the knowledge about the diversity and habitat distribution of cyanobacteria and microalgae on macrophytes found in freshwater habitats in the Philippines.
Siasatan terhadap taburan dan kelimpahan kumpulan pemakanan
makroinvertebrata akuatik di Sungai Bogak, Kerian dan Serdang di lembangan sungai
Kerian menunjukkan terdapat 120 genera dari 59 keluarga dari 13 order makroinvertebrata.
Pemangsa terutamanya Odonata, Hemiptera dan Coleoptera adalah kumpulan yang paling
biasa dan didapati dalam kepadatan tinggi di Sungai Bogak (sungai yang diubah suai)
dan Sungai Kerian (sungai utama). Kumpulan dominan kedua di kedua-dua sungai itu
adalah pemungut-kumpul (Diptera dan Ephemeroptera) diikuti oleh pengikis (moluska).
Pola kumpulan pemakanan yang berlainan diperhatikan di Sungai Serdang (anak Sungai
Kerian). Kumpulan yang paling banyak adalah pemungut-kumpul, diikuti oleh pemangsa
dan pengikis. Secara umum, kelimpahan pemangsa menunjukkan korelasi positif dengan
kelimpahan mangsa mereka (kumpulan pemakanan lain). Kelimpahan pemangsa terutama
di Sungai Bogak dan Kerian, sangat dipengaruhi oleh parameter seperti PO43-, NO3-N
dan Zn. Kelimpahan pemungut-kumpul di sungai Serdang pula dipengaruhi oleh suhu
dan halaju air, TSS, kekeruhan serta kandungan Mn dan Cu di dalam sedimen. Walau
bagaimanapun, semua parameter air mempengaruhi secara lemah kelimpahan kumpulan
pemakanan di semua lokasi. Banyak pemungut-kumpul di Sungai Serdang dikaitkan dengan
air yang diperkaya oleh sisa antropogenik dari kawasan kediaman sekitar. Pada umumnya,
kumpulan pemakanan yang dominan di setiap sungai mencerminkan pengaruh keadaan
persekitaran yang berbeza dan ketersediaan sumber makanan di kawasan tersebut
Penentuan jantina burung adalah penting untuk tujuan kajian ekologi dan biologi evolusi, serta program pembiakan dan konservasi terutamanya bagi burung yang mempunyai ciri monomorfik. Bagi burung pungguk jelapang Tyto alba, pengesahan jantina adalah penting untuk konservasi serta program pengenalan bagi kawalan tikus perosak. Penentuan jantina secara molekular untuk subspesies Asia Tenggara, Tyto alba javanica, telah dijalankan menggunakan Reaksi Rantai Polimerase (PCR) diikuti 3% gel agaros elektroforesis. Primer P2/P8 and 2550F/2718R untuk amplifikasi gen CHD (Chromo Helicase DNA-binding gene) diuji dan kedua-dua set primer memberi keputusan yang berjaya. Set primer 2550F/2718R memberi hasil yang lebih baik kerana jurang di antara jalur berganda lebih terang. DNA yang diekstrak dari darah, darah yang dicairkan, serta DNA yang diekstrak dari bulu burung digunakan untuk menentukan jantina burung. DNA yang diekstrak dari bulu memberi keputusan yang kurang memuaskan akibat pencemaran serta kuantiti DNA yang rendah. Penentuan jantina menggunakan darah yang dicairkan merupakan kaedah yang menjimatkan kos serta masa. Penjujukan gen CHD dari Tyto alba javanica menunjukkan 98% hingga 99% kesamaan identiti bila dibandingkan gen CHD Tyto alba alba.
Pencirian enzim ekstraselular protease daripada bakteria Alkalophilic Bacillus lehensis G1 dari Malaysia telah dikaji. Enzim protease yang dirembeskan diuji pada agar susu skim 2%. Keputusan menunjukkan protease ekstraselular mampu mengekalkan aktiviti sehingga suhu 60°C di dalam julat pH yang luas iaitu 3 hingga 11 dengan suhu optimum pada 40°C dan pH optimum pada 7.0. Aktiviti enzim juga diperhatikan akan meningkat dengan penambahan beberapa ion iaitu Mn2+, Fe2+, Cu2+, Mg2+ dan Co2+. Manakala aktiviti protease didapati sedikit direncat dengan kehadiran ion Ca2+, K+ dan Ni2+ dengan baki aktiviti sebanyak 85%, 81% dan 75%. Protease ekstraselular juga didapati serasi dengan beberapa cecair detergen komersial dari Malaysia, yang menunjukkan protease ini boleh dimanfaatkan sebagai pembersih kotoran pada pakaian. Selain itu, potensi kegunaan protease yang dihasilkan oleh B. lehensis G1 ke atas penguraian gelatin dari filem X-ray yang telah digunakan juga telah dilakukan di dalam kajian ini.
Fasciolosis is a water and food-borne disease caused by the liver fluke Fasciola hepatica and Fasciola gigantica. This disease is widespread in different parts of the world. Lymnaeidae and Planorbidae snails are the intermediate hosts of these flukes. Snail population management is a good tool to control fasciolosis because gastropods represent the weakest link in the life-cycle of trematodes. Chlorophyll can be extracted from any green plant. Chlorophyllin was prepared from spinach in 100% ethanol by using different types of chemicals. The chlorophyll obtained from spinach was transformed into water-soluble chlorophyllin. In the present paper, toxicity of chlorophyllin against the snail Lymnaea acuminata was time and concentration dependent. The toxicity of extracted and pure chlorophyllin at continuous 4 h exposure of sunlight was highest with lethal concentration (LC50) of 331.01 mg/L and 2.60 mg/L, respectively, than discontinuous exposure of sunlight up to 8 h with LC50 of 357.04 mg/L and 4.94 mg/L, respectively. Toxicity of extracted chlorophyllin was noted in the presence of different monochromatic visible lights. The highest toxicity was noted in yellow light (96 h, LC50 392.77 mg/L) and the lowest in green light (96 h, LC50 833.02 mg/L). Chlorophyllin in combination with solar radiation or different wavelength of monochromatic visible lights may become a latent remedy against the snail L. acuminata. It was demonstrated that chlorophyllin was more toxic in sunlight. Chlorophyllin is ecologically safe and more economical than synthetic molluscicides which have the potential to control the incidence of fasciolosis in developing countries.
A survey was conducted to determine the diversity of fish in Pergau Lake, Jeli, Kelantan, Malaysia from 2 September to 18 October of 2016. Fish samples were collected at seven random sampling stations around the lake by using setting trap method. The collected samples were preserved in 10% formalin solution and delivered to the laboratory for further identification process. Fourteen species, namely as Hemibagrus nemurus, Hampala macrolepidota, Clarias batrachus, Channa striata, Cyprinus carpio, Poropuntius smedleyi, Pangasius sp., Oreochromis niloticus, Oreochromis mossambicus, Leptobarbus hoevenii, Neolissochilus hexagonolepis, Tor tambroides, Osteochilus hasselti and Neolissochilus soroides, comprising of six families were collected during this study. From this study, family of Cyprinidae was the dominant species in Pergau Lake with exactly 50% of catch percentage, followed by family of Bagridae (29%), Cichlidae (10%), Clariidae (5%), Channidae (3%) and Pangasiidae (3%). This study shows that there is still a diversity of fish species in Pergau Lake, showing that the water and its environmental condition is very good.
Stevia rebaudiana, a perennial herb native to northeastern Paraguay, has gained immense attention globally over the recent decades due to the natural sweetness of its leaves. Like in most plants, this particular species contains high amount of secondary metabolites, thus rendering the isolation of high quality and quantity RNA extract for molecular applications rather challenging. An effective, high-yield and high-quality RNA isolation protocol for this economically important plant species was devised here based on the cetyltrimethylammonium bromide (CTAB) extraction method, with an additional genomic DNA (gDNA) removal step. DNA and other contaminants that may affect downstream applications were effectively removed. Our results exhibited that RNA samples isolated from the leaves and stems of Stevia rebaudiana using this improvised method are high in integrity and quality with RNA integrity number (RIN) of more than 8 and low in contaminants.