Lantibiotics are ribosomally synthesized antimicrobial peptides with substantial posttranslational modifications. They are characterized by the unique amino acids lanthionine and methyllanthionine, which are introduced by dehydration of Ser/Thr residues and linkage of the resulting dehydrated amino acids with Cys residues. BLAST searches using the mersacidin biosynthetic enzyme (MrsM) in the NCBI database revealed a new class II lantibiotic gene cluster in Bacillus pseudomycoides DSM 12442. Production of an antimicrobial substance with activity against Gram-positive bacteria was detectable in a cell wash extract of this strain. The substance was partially purified, and mass spectrometric analysis predicted a peptide of 2,786 Da in the active fraction. In order to characterize the putative lantibiotic further, heterologous expression of the predicted biosynthetic genes was performed in Escherichia coli. Coexpression of the prepeptide (PseA) along with the corresponding modification enzyme (PseM) resulted in the production of a modified peptide with the corresponding mass, carrying four out of eight possible dehydrations and supporting the presence of four thioether and one disulfide bridge. After the proteolytic removal of the leader, the core peptide exhibited antimicrobial activity. In conclusion, pseudomycoicidin is a novel lantibiotic with antimicrobial activity that was heterologously produced in E. coli.

Rise in multi drug resistant bacteria has been a public health problem. This has necessitated for the exploration of novel antimicrobials. Bacteriocins, probiotic bacteria, and bacteriophages are considered as alternatives to antibiotics. To this context, lantibiotics could be the future candidate for antimicrobial agent. Lantibiotics are synthesized ribosomally and after posttranslational modification active peptide is produced. Lantibiotics are lanthionine and methyllanthionine containing peptides exhibiting activity against multi drug resistant pathogens. Besides its application as alternatives to old antibiotics, they can be used as food preservatives, additives, probiotics, and prophylactics.

Antimicrobial agents, lantibiotics, bacteriocin-like inhibitory substance (BLIS), probiotics Antimicrobial peptides (AMPs) are inherently occurring proteins that are produced by microorganisms as secondary metabolites. Members of genus Bacillus produce many types of AMPs by ribosomal (bacteriocins) and non-ribosomal (polymyxins and iturins) mechanisms. Bacteriocins are ribosomally synthesized peptides that inhibit the growth of closely related bacterial strains. Moreover, bacteriocins produced by Bacillus species have been widely used in pharmaceutical, food industry, fishery, livestock as well as in agriculture sector. The objective of this review is to assess the characterization of the Bacillus-derived bacteriocins, their potential use in different sectors and structure-activity relationships.

Drinking water quality assessment in Kathmandu valley has always been crucial with reference to public health importance. The objective of this study was to assess the quality of drinking water with respect to physiochemical and microbiological parameters. A total of 63 random water samples were collected from different sources like stone spout, tap, well, boring, hand pumps and jar from different wards of Kageshwori Manohara Municipality, Kathmandu. The study was carried out for 6 months from January to July, 2019. The pH of the samples was in the range of 6.5-7.2, temperature 5-19 °C, chloride 0-96.56 mg/L, nitrate 0-5.4 mg/L and iron 0-1.1 mg/L. The physicochemical parameters including pH, temperature, chloride, nitrate of the samples were found to lie within the WHO guideline value except iron where 4 (6.34%) samples including 2 tap, 1 boring and 1 well exceeded WHO guideline. The bacteriological analysis of water samples revealed the presence of total coliform in 35 (55.56%) out of 63 samples, among which 8 (12.69%) were found to have faecal coliform. Furthermore, Salmonella spp. was isolated from 1 out of 63 samples. However, all the samples were free of Shigella spp. and Vibrio spp. It was found that most of the water samples were non potable as total and faecal coliform exceeded the WHO guideline value of drinking water.

Minimization of deleterious effects of chemical fertilizers on health, ecosystem and economy can only be achieved by finding healthy, ecofriendly and cheap alternatives. Naturally selected symbiotic relationship between the endophytic bacteria and their host plants makes them an ideal candidate as biofertilizer. They can synthesize various plant growth hormones as well as assist their host in uptake of nutrients from soil.The study was designed to compare plant growth promotion of Solanum lycopersicum by Bacillus spp., Pseudomonas spp. and total endophytic community isolated from roots of S. lycopersicum, grown in the soil samples collected from various locations of Kathmandu valley of Nepal. Tomato seeds were inoculated with mixtures of eight endophytic strains of Bacillus spp. and Pseudomonas spp., and crude endophytes obtained from each location separately.Endophytic treatments, except Pseudomonas spp., inhibited seminal root growth during 12-days germination period. However, after plantation, root and shoot biomass was enhanced by the endophytes, with no significant differences among the bacterial treatments. The shoot height was also enhanced, among which Pseudomonas spp. had the strongest effect. In phosphate solubilization assay, out of seventy-two isolates each of Bacillus spp. and Pseudomonas spp. tested, twenty-four isolates of Pseudomonas spp. and sixteen isolates of Bacillus spp. could solubilize phosphate. Higher number of phosphate solubilizing isolates of Pseudomonas spp. might provide a possible explanation for the greater enhancement of shoot height by Pseudomonas spp. as compared to Bacillus spp.