Diversity Of Gram-positive Bacteria Research Articles

A STUDY ONANTI-MICROBIAL RESISTANTENVIRONMENTAL BACTERIA FROM AURANGABAD CITY MUNICIPAL AREA MAHARASHTRA, INDIA

With rapid industrial development and progress of civilization, the problem of increase in waste generation becomes more complex in urban areas like Aurangabad fastest growing city in Asia in Marathwada, Maharashtra in India. In this study,we explorethe diversityofbacteriainsewagewastewater withthe assessment oftheantibiotic resistance of the isolated bacteria. The water samples: sewage wastewater was collectedfrominaround the Aurangabad City of Maharashtra, India, and was processed for isolation, which was characterized for identificationfollowingphenotypictechniques.A total of 09 bacteria were isolated from the sewage samples studied, among which 3 were gram-negative and 06 were gram-positive. Our present study evidently revealed that thesewageasconfirmedinthecurrentstudy,the growth ofgram-positive rods shape cocci, and evengram-negative rods too in which the diversity of gram-positivebacteria was found greater, as we compared to the gram-negative bacteria.Thesebacteria isolateshave the potential to cause infections andpossess varied antibiotic resistance. Thus,thisisimperativefortheregularvigilanceofsuchwastewaterbacteriatocombatbacterialmultipleantibioticresistance. We can conclude that the useful bacteria might be isolated from the Aurangabad city area which will be helpful for bioconversion of sewage/solid waste management.

Copsin, a Novel Peptide-based Fungal Antibiotic Interfering with the Peptidoglycan Synthesis

Fungi and bacteria compete with an arsenal of secreted molecules for their ecological niche. This repertoire represents a rich and inexhaustible source for antibiotics and fungicides. Antimicrobial peptides are an emerging class of fungal defense molecules that are promising candidates for pharmaceutical applications. Based on a co-cultivation system, we studied the interaction of the coprophilous basidiomycete Coprinopsis cinerea with different bacterial species and identified a novel defensin, copsin. The polypeptide was recombinantly produced in Pichia pastoris, and the three-dimensional structure was solved by NMR. The cysteine stabilized α/β-fold with a unique disulfide connectivity, and an N-terminal pyroglutamate rendered copsin extremely stable against high temperatures and protease digestion. Copsin was bactericidal against a diversity of Gram-positive bacteria, including human pathogens such as Enterococcus faecium and Listeria monocytogenes. Characterization of the antibacterial activity revealed that copsin bound specifically to the peptidoglycan precursor lipid II and therefore interfered with the cell wall biosynthesis. In particular, and unlike lantibiotics and other defensins, the third position of the lipid II pentapeptide is essential for effective copsin binding. The unique structural properties of copsin make it a possible scaffold for new antibiotics.

English

Petroleum hydrocarbons are species of dangerous contaminants in nature. Scientists are looking for many years to find solution for removing contaminants from the soil and water environments. Today, the use of microorganism, for removing crude oil pollution from contaminated sites (bioremediation) is considered by scientists. The purpose of this research is to isolate and identify hydrocarbons degrading bacteria from Shiraz Refinery soil. In this study, nutrient agar (NA) and mineral salt agar (MM2) were used as basic cultures. Using the Techniques Replica plating, we transferred colonies on NA surface to the MM2 agar. For spraying hydrocarbons on the MM2 agar surface, we used spray plating technique. Finally we have identified different bacterial genera by using biochemical tests and morphological study. Upon examination on morphological studies and biochemical tests, it is determined that these strains belong to bacterial genera as follows: Bacillus, Corynebacterium, Staphylococcus, Streptococcus, Klebsiella, Escherichia, Acinetobacter, Alcaligenes, Shigella. Enterobacter. It is also discovered that these bacteria can break down Biphenyl, Naphthalene, Camphor and Phenenthrene. The results showed that Biphenyl, Naphthalene, Camphor and Phenanthrene were decomposed by 22, 23, 34 and 23%, respectively. Bacillus was 69% of the bacterial population and accounted as the most dominant bacterial genus. Statistical analysis showed that there is a significant relationship with the level of 0.05 among the station, the numbers, and the diversity of Gram-positive bacteria.   Key words: Degrading bacteria, camphor, bioremediation, Bacillus, Shiraz Refinery.

Localisation of DivIVA by targeting to negatively curved membranes

DivIVA is a conserved protein in Gram-positive bacteria and involved in various processes related to cell growth, cell division and spore formation. DivIVA is specifically targeted to cell division sites and cell poles. In Bacillus subtilis, DivIVA helps to localise other proteins, such as the conserved cell division inhibitor proteins, MinC/MinD, and the chromosome segregation protein, RacA. Little is known about the mechanism that localises DivIVA. Here we show that DivIVA binds to liposomes, and that the N terminus harbours the membrane targeting sequence. The purified protein can stimulate binding of RacA to membranes. In mutants with aberrant cell shapes, DivIVA accumulates where the cell membrane is most strongly curved. On the basis of electron microscopic studies and other data, we propose that this is due to molecular bridging of the curvature by DivIVA multimers. This model may explain why DivIVA localises at cell division sites. A Monte-Carlo simulation study showed that molecular bridging can be a general mechanism for binding of proteins to negatively curved membranes.

Microbial community dynamics in a chemolithotrophic denitrification reactor inoculated with methanogenic granular sludge

Denitrification is applied in the tertiary treatment of wastewater to reduce nitrogen pollution. Fluorescence in situ hybridization (FISH), catalyzed reporter deposition (CARD)-FISH, cloning, and scanning electron microscopy (SEM) were applied to follow the evolution of the microbial composition and structure of granular sludge in chemolithotrophic denitrifying bioreactors fed with nitrate and thiosulfate. FISH oligonucleotide probes for the chemolitoautotrophic denitrifiers Thiobacillus denitrificans and Thiomicrospira denitrificans were designed and their utility tested. CARD-FISH and cloning data showed that bacterial diversity in the biofilms changed during the reactor operation. Chemoorganotrophic fermentative Gram-positive strains in the phyla, Actinobacteria and Firmicutes, were dominant in the methanogenic inoculum, both in terms of biodiversity and in number. Other significant phyla were Bacteroidetes and Chloroflexi. After 6 months of operation, Proteobacteria became dominant (83% of the clones). The diversity of Gram-positive bacteria was partially maintained although their abundance decreased notably. After 110 d of operation, the abundance of Tb. denitrificans cells increased considerably, from 1% to 35% of total DAPI-stained cells and from no isolated clones to 15% of the total clones. Tm. denitrificans only represented a minor fraction of the microorganisms in the sludge (1–4% of the DAPI-stained cells). These findings confirm that Tb. denitrificans was the dominant chemolitoautotrophic denitrifying microorganism in the bioreactors. The Archaeal diversity remained almost unchanged and it was represented mostly by Methanosaeta soehngenii. SEM results indicated a considerable loss in the integrity of the sludge granules during the operation, with risk of sludge buoyancy.