Research On The Antimicrobial Active Substances From Marine Anaerobic Bacteria SRB-22 And PSB-11

It is well known that terrestrial microorganism, once formed a brilliant era of antibiotics, has become an important resource of antibiotics, enzyme inhibitors and other bioactive substances. However, with the extensive use of antibiotics, two issues have been raised in clinical practice. First, bacterial resistance has increased year by year, resulting in effect decreased or even no effect of some antibiotics. Another problem is that some non-pathogenic bacteria become opportunistic pathogen, causing a certain threatin in clinical practice. So new antibiotics of new structure and new mechanisms of antibacterial activity need to be screened continuously in order to meet clinical needs. However, through the long-term study of terrestrial micro-organism, this ancient resources have become increasingly exhausted, so it is urgently necessary for us to broaden new way for drugs. Ocean has a unique natural conditions, high pressure, low-nutrition, no light, local high-temperature, high salt, making marine micro-organisms have special metabolic pathway and genetic background, Which has great potential of producing active substances with special structure and function. It was found that about 27% of marine micro-organisms can produce antibiotic substances, which has become an important source of screening new antibiotics.In this research, an antimicrobial sulfate-reducing bacterium SRB-22 and an antimicrobial photosynthetic bacterium PSB-11, isolated from the sea water sample of Heishijiao sea area in Dalian, were studied on those fermentation conditions,and their antimicrobial active substances. Main results are as follows:The effect of fermentation time on the bioactive substances production was determined. A method of tandem use of macroporous adsorptive resin NKA was established for extracting the antimicrobial active products from the fermentation broth. By experiments, the optimal fermentation time was determined to be 28 d. The suitable extraction process was streamlined. First fermentation broth was treated by sand filter, subsequently extract with NKA resin column at pH 6.0. From 150 L fermentation broth, 10.00 g of crude extract was obtained. One active aubstances was obtained, then indentified as mono-n-butyl phthalate by spectral analysis of 1H-NMR, 13C-NMR, DEPT-90 and DEPT-135 as well as by comparison with data reported in reference.