Fresh vegetables can be used as a source of antifungal lactic acid bacteria. Their exploitation as biopreservative will help in prolonging shelf-life of fresh vegetables.

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Aim: Purification and characterization of a chitinase from Microbispora sp. V2. Methods and Results: The chitinase from Microbispora sp. V2 was purified to homogeneity by gel filtration chromatography with 4AE6% recovery. It had a molecular weight of 35 kDa and showed maximum activity towards p-nitrophenyl-b-D D-N,N¢-diacetylchitobiose, indicating a chitobiosidase activity. The enzyme had a pH optimum of 3AE0 and temperature optimum of 60°C. It was stable in a wide pH range from 3AE0 to 11AE0, retaining 61% activity at pH 3AE0 and 52% activity at pH 11AE0. It retained 71% activity at 30°C and 45% activity at 50°C, up to 24 h. The enzyme activity was not inhibited by any of the metal ions tested except Hg 2+ , in the presence of which only 10% activity was retained. Conclusions: The 35 kDa chitinase from Microbispora sp. V2 has an acidic pH optimum and a high temperature optimum. It is fairly stable and active, and degrades chitin efficiently, although the growth of the culture and enzyme production is slow. Significance and Impact of the Study: This report is the first detailed study of a chitinase from Microbispora sp. V2, isolated from hot springs. The chitinase from Microbispora sp. V2 may have potential applications in the recycling of chitinous wastes, particularly due to its thermophilic and acidophilic character. Studies at molecular level may provide further insight on the chitinolytic system of Microbispora spp. with respect to the number and types of chitinases and their regulation.

Biocatalysis, one of the oldest technologies, is becoming a favorable alternative to chemical processes and a vital part of green technology. It is an important revenue generating industry due to a global market projected at $7 billion in 2013 with a growth of 6.7% for enzymes alone. Some microbes are important sources of enzymes and are preferred over sources of plant and animal origin. As a result, more than 50% of the industrial enzymes are obtained from bacteria. The constant search for novel enzymes with robust characteristics has led to improvisations in the industrial processes, which is the key for profit growth. Actinomycetes constitute a significant component of the microbial population in most soils and can produce extracellular enzymes which can decompose various materials. Their enzymes are more attractive than enzymes from other sources because of their high stability and unusual substrate specificity. Actinomycetes found in extreme habitats produce novel enzymes with huge commercial potential. This review attempts to highlight the global importance of enzymes and extends to signify actinomycetes as promising harbingers of green technology.

The main objective of this study was to identify and isolate arsenic resistant bacteria that can be used for removing arsenic from the contaminated environment. Here we report a soil borne bacterium, B1-CDA that can serve this purpose. B1-CDA was isolated from the soil of a cultivated land in Chuadanga district located in the southwest region of Bangladesh. The morphological, biochemical and 16S rRNA analysis suggested that the isolate belongs to Lysinibacillus sphaericus. The minimum inhibitory concentration (MIC) value of the isolate is 500 mM (As) as arsenate. TOF-SIMS and ICP-MS analysis confirmed intracellular accumulation and removal of arsenics. Arsenic accumulation in cells amounted to 5.0 mg g(-1) of the cells dry biomass and thus reduced the arsenic concentration in the contaminated liquid medium by as much as 50%. These results indicate that B1-CDA has the potential for remediation of arsenic from the contaminated water. We believe the benefits of implementing this bacterium to efficiently reduce arsenic exposure will not only help to remove one aspect of human arsenic poisoning but will also benefit livestock and native animal species. Therefore, the outcome of this research will be highly significant for people in the affected area and also for human populations in other countries that have credible health concerns as a consequence of arsenic-contaminated water.

In the current era, an ever-emerging threat of multidrug-resistant (MDR) pathogens pose serious health challenges to mankind. Researchers are uninterruptedly putting their efforts to design and develop alternative, innovative strategies to tackle the antibiotic resistance displayed by varied pathogens. Among several naturally derived and chemically synthesized compounds, quinones have achieved a distinct position to defeat microbial pathogens. This review unleashes the structural diversity and promising biological activities of naphthoquinones (NQs) and their derivatives documented in the past two decades. Further, realizing their functional potentialities, researchers were encouraged to approach NQs as lead molecules. We have retrieved information that is dedicated on biological applications (antibacterial, antifungal, antiparasitic) of NQs. The multiple roles of NQs offer them a promising armory to combat microbial pathogens including MDR and the ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp.) group. In bacteria, NQs may exhibit their function in the following ways (1) plasmid curing, (2) inhibiting efflux pumps (EPs), (3) generating reactive oxygen species (ROS), (4) the inhibition of topoisomerase activity. Sparse but meticulous literature suggests the mechanistic roles of NQs. We have highlighted the possible mechanisms of NQs and how the targeted drug synthesis can be achieved via molecular docking analysis. This bioinformatics-oriented approach will explicitly lead to the development of effective and most potent drugs against targeted pathogens. The mechanistic approaches of emerging molecules like NQs might prove a milestone to defeat the battle against microbial pathogens.

Aims: A simple single step technique of gel ®ltration was developed for the puri®cation of chitinase from Serratia marcescens NK1. Methods and Results: Chitinase from Ser. marcescens NK1 was puri®ed to homogeneity by gel ®ltration chromatography with 9á2% recovery. The enzyme had a pH optimum of 6á2 and a temperature optimum of 47°C. It was stable in a wide pH range of 3á0 to 10á0, retaining 60% activity at pH 3á0 and 65% activity at pH 10á5. It retained 70% activity at 28°C after 72 h and nearly 50% activity at 50°C up to 24 h. Conclusions: The chitinase from Ser. marcescens NK1 can be ef®ciently puri®ed in a single step by gel ®ltration chromatography. The chitinase of Ser. marcescens NK1, a soil isolate, is highly stable and as active as that of other reported isolates of Ser. marcescens. Signi®cance and Impact of the Study: This puri®cation scheme is advantageous because of its simplicity and can therefore be applied for the puri®cation of other enzymes. The yield is suf®cient for initial characterization studies of the enzyme, and an improved resolution can be obtained if the chromatography is done under fast¯ow systems.