Screening of microorganisms for hydrolyases with commercial potential

Advancement in green chemistry has increased the use of microbial hydrolyases in various industries and chemical processes because of high catalytic efficiency, specificity, cost-effectiveness and eco-friendly nature. Bioconversion of tannins such as tannic acid is achieved by tannin acyl hydrolase, also known as tannase. It converts tannic acid into glucose and gallic acid by catalyzing the hydrolysis of ester and depside linkages in tannic acid. Tyrosinase is monophenol and O-diphenol oxidase a copper containing enzyme catalyzes the oxidation of tyrosine and generates different types of pigment such as melanin. Xylanases hydrolyze xylan into its constituent sugar with the help of several debranching enzymes. Microbial strains isolated from various sources were screened for these hydrolyases: Bhavnagar marine salterns (Bacillus megaterium BVUC_01 and Bacillus licheniformis BVUCh_02); Okhamadhi marine salterns Aspergillus versicolor; Spoiled/infected pomegranate (Xenoacremonium falcatum, two strains PGF1 and PGF4, Bacillus velezensisPGF2 and Candida freyschussiiPGF3. The other laboratory maintained bacterial cultures namely, Bacillus subtilis, Pseudomonas aeruginosa, Staphylococcus aureus, Salmonella typhi were also used in this study. Asp. versicolor and Xen. falcatum (PGF1) produced all the three enzymes (tannase, tyrosinase and xylanase). B. licheniformis, B. megaterium, B. subtilis, B. velezensis produced tyrosinase and xylanase. Xen. falcatum (PGF4) and PGF2 produced tannase and xylanase. PGF3 produced tannase and tyrosinase. While, Bacillus megaterium and Salmonella typhi showed only tyrosinase activity. Candida freyschussii showed tannase activity. Staphylococcus aureus did not produce any of these enzymes.

A Review on the Resistance and Accumulation of Heavy Metals by Different Microbial Strains

Heavy metals accumulated the earth crust and causes extreme pollution. Accumulation of rich concentrations of heavy metals in environments can cause various human diseases which risks health and high ecological issues. Mercury, arsenic, lead, silver, cadmium, chromium, etc. are some heavy metals harmful to organisms at even very low concentration. Heavy metal pollution is increasing day by day due to industrialization, urbanization, mining, volcanic eruptions, weathering of rocks, etc. Different microbial strains have developed very efficient and unique mechanisms for tolerating heavy metals in polluted sites with eco-friendly techniques. Heavy metals are group of metals with density more than 5 g/cm3. Microorganisms are generally present in contaminated sites of heavy metals and they develop new strategies which are metabolism dependent or independent to tackle with the adverse effects of heavy metals. Bacteria, Algae, Fungi, Cyanobacteria uses in bioremediation technique and acts a biosorbent. Removal of heavy metal from contaminated sites using microbial strains is cheaper alternative. Mostly species involved in bioremediation include Enterobacter and Pseudomonas species and some of bacillus species too in bacteria. Aspergillus and Penicillin species used in heavy metal resistance in fungi. Various species of the brown algae and Cyanobacteria shows resistance in algae.

Pneumonic Plague: Incidence, Transmissibility and Future Risks

Pneumonic plague outbreaks are relatively infrequent in modern times, but in the early part of the 20th century, they were commonplace including several well-documented epidemics responsible for the deaths of thousands. The transmissibility of this disease seems to be discontinuous since in some outbreaks few transmissions occur, while in others, the progression of the epidemic is explosive. Modern epidemiological studies explain that transmissibility within populations is heterogenous with relatively few subjects likely to be responsible for most transmissions and that ‘super spreading events’, particularly at the start of an outbreak, can lead to a rapid expansion of cases. These findings concur with outbreaks observed in real-world situations. It is often reported that pneumonic plague is rare and not easily transmitted but this view could lead to unnecessary complacency since future risks such as the spontaneous incidence of anti-microbial strains, climate change leading to a disruption of natural cycles within plague foci and use of plague as a bioweapon cannot be discounted. Carers and first responders are vulnerable, particularly in poorer countries where access to medicines and protection equipment may be limited, outbreaks occur in inaccessible areas or where there is a lack of surveillance due to a paucity of funds.

IMPACT OF ORGANIC AND BIOFERTILIZER APPLICATION ON YIELD AND YIELD ATTRIBUTING CHARACTERS IN LINSEED (Linum usitatissimum L.)

Linseed (Linum usitatissimum L.) belongs to family Linaceae, is the second most important rabi oilseed crop and stands next to rapeseed – mustard in area of cultivation and seed production in India. Flaxseed is grown as either oil crop or a fibre crop with fibre linen derived from the stem of fibre varieties and oil from the seed of linseed varieties. Several studies have been conducted on effect of fertilizers on growth and yield of linseed (Linum usitatissimum L.) varieties which revealed their enhancing role on the quality and quantity of flax cultivars. In this regards, a present study was planned and conducted during the Rabi season of 2020-2021 in the Agricultural field of School of Agricultural Sciences, Shri Guru Ram Rai University, Dehradun, Uttarakhand, India to investigate the effect of organic and biofertilizer and integrated treatment on the growth and yield of Linseed. The findings were reported on important growth and yield attributed parameters such as plant height, total fresh weight, total yield, 1000- seed weight (g), and number of seed / capsules. The maximum growth and yield was reported in T6 treatment where biofertilizer have been applied in consortium form followed by vermicompost. Thus, the findings revealed that all the microbial strains in consortia used as bio fertilizers showed enhanced tern of vegetative growth of plants, total herbage yield and total seed yield at various stages. This may be due to sustained release of nutrients to supply the required elements in microbial strains. The biofertilizers exhibited beneficial effects on plant growth and development either through producing growth hormones like IAA, kinetin and gibberellins, synthesizing atmospheric nitrogen and its increased availability to greater protein synthesis as well as increasing Phosphorus availability to plant communities. Thus, it was concluded that the enhanced expression of yield and its related attributes will have beneficial impact in production of nutraceutical products of commercial importance.

A Genomic Comparative Analysis of Bacillus Coagulans Unravels the Genetic Potential of MA-13 Strain for Biotechnological Applications

The production of bio-chemicals requires the use of microbial strains with efficient substrate conversion and excellent environmental robustness, such as Bacillus coagulans spp. So far the genomes of about 50 strains have been sequenced. Herein, we report a comparative genomic analysis of nine strains on the full repertoire of CAZymes, secretion systems, and resistance mechanisms to environmental challenges. Moreover, B. coagulans Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) immune system along with CRISPR-associated Cas) genes, was also analysed. Overall, this study expands our understanding of the strains genomic diversity of B. coagulans to fully exploit its potential in biotechnological applications.

Antimicrobial Activity of 3D-Printed Acrylonitrile Butadiene Styrene (ABS) Polymer-Coated with Silver Nanoparticles

Medical devices with antimicrobial properties are a potential long-term solution to the high rate of multi-drug-resistant healthcare-associated infections. Silver nanoparticles (AgNPs) are an established agent for effectively eliminating a wide range of microbial strains. AgNPs have been commonly incorporated into traditional plastic materials; however, recently, there has been increased interest in using AgNPs combined with 3D-printing technology for medical devices due to the accessibility and customizability of 3D-printed products. This study reports a novel method of utilizing acetone to partially dissolve 3D-printed polymer acrylonitrile butadiene styrene (ABS) plastic to attach a layer of AgNPs. The antimicrobial properties of this AgNP-coated surface were tested against several microbial strains prevalent in healthcare-associated infections. AgNP-coated ABS (AgNP-ABS) plastic demonstrated significant elimination of viable bacteria within 4 h for all tested bacterial species (Acinetobacter baumannii, non-pathogenic and pathogenic Escherichia coli, Pseudomonas aeruginosa, and methicillin-resistant Staphylococcus aureus) and within 19 h for the tested fungus Candida albicans. The longevity of adhesion of AgNPs to the ABS plastic was assessed by checking antibacterial activity against A. baumannii after repeat use cycles. AgNP-ABS plastic showed decreased antibacterial efficacy with repeated use but maintained the ability to eliminate microbes within 3 h for up to eight use cycles. The AgNP-coated ABS plastic showed efficacy as an antimicrobial surface, and future studies will consider its applicability in the production of medical devices.

Isolation and Identification of Bacteria with Surface and Antibacterial Activity from the Gut of Mediterranean Grey Mullets

Fish gut represents a peculiar ecological niche where bacteria can transit and reside to play vital roles by producing bio-compounds with nutritional, immunomodulatory and other functions. This complex microbial ecosystem reflects several factors (environment, feeding regimen, fish species, etc.). The objective of the present study was the identification of intestinal microbial strains able to produce molecules called biosurfactants (BSs), which were tested for surface and antibacterial activity in order to select a group of probiotic bacteria for aquaculture use. Forty-two bacterial isolates from the digestive tracts of twenty Mediterranean grey mullets were screened for testing emulsifying (E-24), surface and antibiotic activities. Fifty percent of bacteria, ascribed to Pseudomonas aeruginosa, Pseudomonas sp., P. putida and P. anguilliseptica, P. stutzeri, P. protegens and Enterobacter ludwigii were found to be surfactant producers. Of the tested strains, 26.6% exhibited an antibacterial activity against Staphylococcus aureus (10.0 ± 0.0–14.5 ± 0.7 inhibition zone), and among them, 23.3% of isolates also showed inhibitory activity vs. Proteus mirabilis (10.0 ± 0.0–18.5 ± 0.7 mm inhibition zone) and 6.6% vs. Klebsiella pneumoniae (11.5 ± 0.7–17.5 ± 0.7 mm inhibition zone). According to preliminary chemical analysis, the bioactive compounds are suggested to be ascribed to the class of glycolipids. This works indicated that fish gut is a source of bioactive compounds which deserves to be explored.