Novel Bioactive Compound Production by Microbial Biota: Potential Antimicrobials Potential antimicrobials produced by microbial biota

Man is always trying to make his life easier and accomplished. He has faced mass destruction in history due to epidemics like small pox, malaria and plague. In order to combat diseases, exploration of man led him to search for causative agents and their control. A time reached when it was found that microbes are themselves a source of potent metabolites which have proved to be effective as drugs and medicines showing great antibiotic activity. It is necessary to find out new sources for potential new antimicrobial compounds. Several hundred important compounds have been isolated which have antibiotic activities and diverse chemical nature. But these compounds should have minimum toxicity to be useful clinically. Because of the increasing resistance of pathogens, there was a never ending desire and need to search for more. Bioactive Compounds have been extracted from microbes which are produced as secondary metabolites. Day by day, new compounds are being discovered giving a hope of golden future of drug industry. The current article emphasizes the importance and need to search for new bioactive compoundsto overcome infections caused by multiple drug resistant (MDR) and biofilm forming pathogens irrespective of the previously present knowledge. 

Investigation of Differences in Salt Tolerance Mechanisms in Contrasting Bread Wheat Genotypes

The genotypic differences regarding Na + accumulation and transport in plant along with physiological response to improve salt tolerance were studied in bread wheat genotypes. Four wheat genotypes; Kharchia-65, SARC-3, S-9476 and S-8189 were grown under salt stress (75 and 150 mM NaCl) in nutrient solution with five replications. Shoot dry weight, relative growth rate (RGR), chlorophyll index, leaf water relations, Na + content and transport in plant were measured. The increase in NaCl stress decreased all growth parameters, however, variations were observed among genotypes. Kharchia-65, S-9476 and SARC-3 had better growth and water relations compared to salt sensitive genotypes S-8189. The low rate of Na + transport and better ability to restrict Na + in the root was main reason of genetic variation among different genotypes, especially, when growth characteristic did not vary significantly under salt stress. Na + partition was also recorded in wheat genotypes as salt sensitive genotypes had higher Na + accumulation in shoot while it was reverse in tolerant ones. The differences in root Na + were not significant among all genotypes. In many crop plants, over-accumulation of Na + in shoot is the main cause of yield reduction due to toxicity. In this study, wheat genotypes differed mainly because of low rates of Na + uptake and transport from root to shoot. Therefore, in this study, it was concluded that wheat genotypes with contrasting leaf Na + uptake rates and transport from root to shoot had resulted in differences in salinity tolerance. The wheat genotypes having ability to reduce Na + accumulation in shoot by retaining it at root level had better salt tolerance. The genotypes with the highest Na + uptake had lower chlorophyll, more electrolyte leakage, and a slightly lower RGR. Keywords: Genotypes, ion partition, salinity stress, sodium, wheat