ABSTRACT
This study aimed to identify thermo-stable pullulanase-producing bacteria in soil samples of potato fields and food-producing companies. Pullulan agar medium was used to screen 17 bacterial strains, which were incubated at 65 °C. The isolate with the maximum activity (375U/ml) was selected and recognized as Geobacillus stearothermophilus ADM-11 by morphological, biochemical characterization, and 16S rRNA gene sequencing. The pullulanase production required optimum pH of 7 and temperature of 75 °C, respectively. The electrophoresis of purified pullulanase on SDS-polyacrylamide gel revealed 83 kDa of a molecular weight that is active at 70 °C and pH 7.0. It was also stable at 90 °C but its activity was decreased by 10 % at 100 °C. The action of pullulanase was increased and stabilized by Ca+2 among the metal ions. Beta and gamma-cyclodextrins inhibited enzyme activity while ethylenediaminetetraacetate (EDTA) and phenylmethylsulfonyl fluoride (PMSF) have no significant effect on pullulanase activity. A full-length pullulanase gene was amplified from G. stearothermophilus ADM-11 using genomic DNA 2.1 kb of PCR product which was then purified and ligated in the cloning vector pTZ57R using the TA cloning technique. Colony PCR confirmed cloning on the positive clones after the pullulanase gene had been ligated and subjected to restriction digestion. It revealed 74 % similarity with the reported pullulanase gene from Geobacillus sp. 44C. The thermostability of pullulanase and its ability to degrade raw pullulan may therefore have wide-scale applications in starch processing, the detergent business, and new biotechnological applications.
ABSTRACT
In the present study, the effect of probiotics on the hematology of Wistar rats was examined. Locally isolated Lactobacillus plantarum MZ707748 (Pro 1), L. plantarum MZ710117 (Pro 2), Weisella confusa MZ727611 (Pro 3), and L. plantarum MZ735961 (Pro 4) were used. One strain of probiotic, L. acidophilus-14 (Pro 5), was purchased commercially. Different groups were designed as G1, G2, G3, G4, and 5, G5/PC consisting only pro 5 and NC & 0 day were untreated. Different groups have different probiotics like G1 containing Pro 1 and Pro 2, G2 comprising Pro 3 and Pro 4, G3 containing Pro 2, Pro 3 and Pro 5, G4 having Pro 1-5, and G5 containing Pro 5. A complete count of blood, serum chemistry, fecal analysis, and histopathological examination of the thymus and liver were done. Statistical differences were seen in the complete blood count parameters (p < 0.05). No difference was observed in AST, ALT, bilirubin, albumin, IL-6, and IgA (p > 0.05) except for TP, creatinine, and globulin (p < 0.05). Fecal strains of probiotic groups were antibiotic-resistant. In males, Lactobacillus helveticus OQ152020, Enterococcus lactis OQ1519891, E. faecium OQ152017, L. gasseri OQ152017, and E. lactis OQ152019 were isolated from positive control, G1, G2, G3, and G4 respectively. In females, Enterococcus sp. OP800231, Limosilactobacillus fermentum OQ151985, E. lactis OP800267, L. plantarum OP800244, and E. faecium OQ151988 were isolated from positive control, G1, G2, G3 and G4, respectively. It was concluded that all probiotic strains were safe to use and had beneficial effects on the hematology of Wistar rats.
ABSTRACT
A multiple metal-resistant Brevibacterium sp. strain CS2, isolated from an industrial wastewater, resisted arsenate and arsenate upto 280 and 40 mM. The order of resistance against multiple metals was Arsenate > Arsenite > Selenium = Cobalt > Lead = Nickel > Cadmium = Chromium = Mercury. The bacterium was characterized as per morphological and biochemical characteristics at optimum conditions (37 â and 7 pH). The appearance of brownish color precipitation was due to the interaction of silver nitrate confirming its oxidizing ability against arsenic. The strain showed arsenic processing ability at different temperatures, pH, and initial arsenic concentration which was 37% after 72 h and 48% after 96 h of incubation at optimum conditions with arsenite 250 mM/L (initial arsenic concentration). The maximum arsenic removal ability of strain CS2 was determined for 8 days, which was 32 and 46% in wastewater and distilled water, respectively. The heat-inactivated cells of the isolated strain showed a bioremediation efficiency (E) of 96% after 10 h. Genes cluster (9.6 kb) related to arsenite oxidation was found in Brevibacterium sp. strain CS2 after the genome analysis of isolated bacteria through illumine and nanopore sequencing technology. The arsenite oxidizing gene smaller subunit (aioB) on chromosomal DNA locus (Prokka_01508) was identified which plays a role in arsenite oxidation for energy metabolism. The presence of arsenic oxidizing genes and an efficient arsenic oxidizing potential of Brevibacterium sp. strain CS2 make it a potential candidate for green chemistry to eradicate arsenic from arsenic-contaminated wastewater.
ABSTRACT
Due to rising populations and human activities, heavy metals (HM) toxicity has become a serious problem for all life forms. The present study deals with isolating and identifying lead-resistant bacteria from contaminated wastewater of tanneries effluents. Two isolated strains were identified as Bacillus cereus (ID1), and Bacillus sp. (ID3), and both strains resisted a 25 mM concentration of Lead nitrate (Pb (NO3)2). After four days of treatment, Bacillus cereus (ID1) showed 80% lead uptake, and Bacillus sp. (ID3) showed 88%. Lead uptake was confirmed by Energy dispersive X-Ray (EDX) analysis. Fourier transform infrared spectroscopy (FTIR) showed that structural alterations had occurred in functional groups of the treated samples compared to the controls. Our research indicates that these Bacillus strains may be useful in bioremediating heavy metals from polluted environments. Further investigation into the processes involved in the uptake and homeostasis of heavy metals by these strains is required, as is the identification of the genes and enzymes responsible for Pb-bioremediation.
ABSTRACT
Probiotics were isolated from fruits and vegetables. Microscopic, biochemical, and molecular tests were carried out for the characterization of strains of probiotics. To assess the effects of isolated probiotics on immunity, male and female (15 + 15) Wistar rats (n = 3) were randomly distributed into 5 groups: 0-day, negative control, positive control (commercially available Lactobacillus acidophilus-14), laboratory isolated probiotics with accession numbers; Lactobacillus plantarum (MZ707748) and Lactobacillus plantarum (MZ729681), respectively. After hematological investigations, the amounts of IgA and IgG in male and female groups were significantly different (p < 0.05). At the same time, the values of Alanine-transaminase (ALT) and Aspartate-aminotransferase (AST) in both genders were average, and there were no differences (p > 0.05). Male probiotic-treated groups had decreased levels of interleukin-6, bilirubin, and creatinine, but female probiotic-treated groups had a slight rise in bilirubin and creatinine values (p = 0.05). Cellular blood count levels of Hematocrit (HCT) and white blood cells (WBC) in male groups showed considerable differences (p < 0.05), while there were no differences (p > 0.05) in female groups. Levels of Red blood cells (RBC) and mean corpuscular hemoglobin concentration (MCHC) showed distinct changes (p < 0.05) in female groups, while these values were insignificant changes (p > 0.05) among male groups. There were considerable differences between the control and groups that were given probiotics. Histopathological results showed no damage to the liver and thymus. A fecal examination of rats was used to examine the viability and survival of Lactobacilli. Based on blood tests, it was observed that the immune system was boosted and improved in probiotic-treated groups compared to control groups.
