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Culture-independent-based analyses identified site-specific microbial in two oil-wells from Malaysia

Cheng-Yee Fish-Low, Chee HY, Ainon Hamzah

Sains Malaysiana, 2015;44:1625-1633.

Microbial communities of two oil reservoirs from Malaysia, denoted as Platform Bo and Platform Pe were studied using
culture-independent approach. Environmental DNA was extracted and the universal amplified ribosomal region (UARR)
was target amplified for both prokaryotes and eukaryotes. The amplified products were purified and cloned into pTZ57R/T
vector to construct the 16S/18S rDNA library. Restriction endocucleases HhaI and MspI were used to screen the library.
From that, 125 and 253 recombinant plasmid representative clones from Platform Bo and Platform Pe, respectively, were
sent for DNA sequencing. Twenty-six operational taxonomic units (OTUs) consist of 20 genera detected at Platform Bo
and 17 OTUs consist of 13 genera detected at Platform Pe. Marinobacter and Acinetobacter species co-occurred in both
platforms whereas the rest are site-specific. Gammaproteobacteria accounted for 86.0% of the microbial community in
Platform Bo, where OTUs affiliated to Marinobacter, Pseudomonas and Marinobacterium that were the most abundant. The
major OTUs in the Platform Pe were with affinities to Achromobacter, followed by Stenotrophomonas and Serratia. The
only archaeal isolates were detected in Platform Pe, which affiliated to Thermocladium. The singletons and doubletons
accounted for about 50.0% of the OTU abundance in both platforms, which considerably significant despite their rare
occurrence.

Matched MeSH terms: Eukaryota
Fulltext Chlorella vulgaris Modulates Genes and Muscle-Specific microRNAs Expression to Promote Myoblast Differentiation in Culture

Zainul Azlan N, Mohd Yusof YA, Alias E, Makpol S

Evid Based Complement Alternat Med, 2019;2019:8394648.
PMID: 31428175 DOI: 10.1155/2019/8394648

Background: Loss of skeletal muscle mass, strength, and function due to gradual decline in the regeneration of skeletal muscle fibers was observed with advancing age. This condition is known as sarcopenia. Myogenic regulatory factors (MRFs) are essential in muscle regeneration as its activation leads to the differentiation of myoblasts to myofibers. Chlorella vulgaris is a coccoid green eukaryotic microalga that contains highly nutritious substances and has been reported for its pharmaceutical effects. The aim of this study was to determine the effect of C. vulgaris on the regulation of MRFs and myomiRs expression in young and senescent myoblasts during differentiation in vitro.
Methods: Human skeletal muscle myoblast (HSMM) cells were cultured and serial passaging was carried out to obtain young and senescent cells. The cells were then treated with C. vulgaris followed by differentiation induction. The expression of Pax7, MyoD1, Myf5, MEF2C, IGF1R, MYOG, TNNT1, PTEN, and MYH2 genes and miR-133b, miR-206, and miR-486 was determined in untreated and C. vulgaris-treated myoblasts on Days 0, 1, 3, 5, and 7 of differentiation.
Results: The expression of Pax7, MyoD1, Myf5, MEF2C, IGF1R, MYOG, TNNT1, and PTEN in control senescent myoblasts was significantly decreased on Day 0 of differentiation (p<0.05). Treatment with C. vulgaris upregulated Pax7, Myf5, MEF2C, IGF1R, MYOG, and PTEN in senescent myoblasts (p<0.05) and upregulated Pax7 and MYOG in young myoblasts (p<0.05). The expression of MyoD1 and Myf5 in young myoblasts however was significantly decreased on Day 0 of differentiation (p<0.05). During differentiation, the expression of these genes was increased with C. vulgaris treatment. Further analysis on myomiRs expression showed that miR-133b, miR-206, and miR-486 were significantly downregulated in senescent myoblasts on Day 0 of differentiation which was upregulated by C. vulgaris treatment (p<0.05). During differentiation, the expression of miR-133b and miR-206 was significantly increased with C. vulgaris treatment in both young and senescent myoblasts (p<0.05). However, no significant change was observed on the expression of miR-486 with C. vulgaris treatment.
Conclusions: C. vulgaris demonstrated the modulatory effects on the expression of MRFs and myomiRs during proliferation and differentiation of myoblasts in culture. These findings may indicate the beneficial effect of C. vulgaris in muscle regeneration during ageing thus may prevent sarcopenia in the elderly.

Matched MeSH terms: Eukaryota
Fulltext Strong and widespread cycloheximide resistance in Stichococcus-like eukaryotic algal taxa

Syuhada NH, Merican F, Zaki S, Broady PA, Convey P, Muangmai N

Sci Rep, 2022 Jan 20;12(1):1080.
PMID: 35058560 DOI: 10.1038/s41598-022-05116-y

This study was initiated following the serendipitous discovery of a unialgal culture of a Stichococcus-like green alga (Chlorophyta) newly isolated from soil collected on Signy Island (maritime Antarctica) in growth medium supplemented with 100 µg/mL cycloheximide (CHX, a widely used antibiotic active against most eukaryotes). In order to test the generality of CHX resistance in taxa originally identified as members of Stichococcus (the detailed taxonomic relationships within this group of algae have been updated since our study took place), six strains were studied: two strains isolated from recent substrate collections from Signy Island (maritime Antarctica) ("Antarctica" 1 and "Antarctica" 2), one isolated from this island about 50 years ago ("Antarctica" 3) and single Arctic ("Arctic"), temperate ("Temperate") and tropical ("Tropical") strains. The sensitivity of each strain towards CHX was compared by determining the minimum inhibitory concentration (MIC), and growth rate and lag time when exposed to different CHX concentrations. All strains except "Temperate" were highly resistant to CHX (MIC > 1000 µg/mL), while "Temperate" was resistant to 62.5 µg/mL (a concentration still considerably greater than any previously reported for algae). All highly resistant strains showed no significant differences in growth rate between control and treatment (1000 µg/mL CHX) conditions. Morphological examination suggested that four strains were consistent with the description of the species Stichococcus bacillaris while the remaining two conformed to S. mirabilis. However, based on sequence analyses and the recently available phylogeny, only one strain, "Temperate", was confirmed to be S. bacillaris, while "Tropical" represents the newly erected genus Tetratostichococcus, "Antarctica 1" Tritostichococcus, and "Antarctica 2", "Antarctica 3" and "Arctic" Deuterostichococcus. Both phylogenetic and CHX sensitivity analyses suggest that CHX resistance is potentially widespread within this group of algae.

Matched MeSH terms: Eukaryota
Fulltext Eukaryotic pathways targeted by the type III secretion system effector protein, BipC, involved in the intracellular lifecycle of Burkholderia pseudomallei

Kang WT, Vellasamy KM, Vadivelu J

Sci Rep, 2016 09 16;6:33528.
PMID: 27634329 DOI: 10.1038/srep33528

Burkholderia pseudomallei, the etiological agent for melioidosis, is known to secrete a type III secretion system (TTSS) protein into the host's internal milieu. One of the TTSS effector protein, BipC, has been shown to play an important role in the B. pseudomallei pathogenesis. To identify the host response profile that was directly or indirectly regulated by this protein, genome-wide transcriptome approach was used to examine the gene expression profiles of infected mice. The transcriptome analysis of the liver and spleen revealed that a total of approximately 1,000 genes were transcriptionally affected by BipC. Genes involved in bacterial invasion, regulation of actin cytoskeleton, and MAPK signalling pathway were over-expressed and may be specifically regulated by BipC in vivo. These results suggest that BipC mainly targets pathways related to the cellular processes which could modulate the cellular trafficking processes. The host transcriptional response exhibited remarkable differences with and without the presence of the BipC protein. Overall, the detailed picture of this study provides new insights that BipC may have evolved to efficiently manipulate host-cell pathways which is crucial in the intracellular lifecycle of B. pseudomallei.

Matched MeSH terms: Eukaryota/metabolism*