Isolation, Identification And Application Of The Halophilic Bacteria

Moderate halophilic bacterium had a wide rang to adapt to the salt-stress, and wasused in different fields. In recent years, more and more attention were paid on theenvironmental biological treatment and the production of compatible solutes bymoderate halophilic bacterium.This paper mainly studied eight microorganisms obtained from different saline soils,the point was halophilic bacterium Halmonas elogata from Xinjiang UygurAutomomous Region. Firstly, The growth characteristics of H. elogata was studied.Secondly, degradation of azo dye Reactive Blue BRF dyeing wasterwater with the strainH. elogata under conditions of5%NaCl and the secretion of compatible solutes ectoinefacing with imbalance in osmotic pressure. Thirdly, made microbial fertilizer andinvestigated microbial bacterial fertilizer-Suaeda repairing saline-alkali soilcollaborativly. The prime results were as follows:1There were eight miroorganisms from Qingdao Wang ge zhuang, Saltern,Xinjiang Uygur Automomous Region and Yulin, including four kinds of the bacteria,two actinomyces and two fungus. Bacterium N1, N2and N3was salt-tolerantGram-negative bacteria, which could grow in less than10%NaCl medium; the strainN4had a wide toleration of salt, it could tolerate the salt concentration range of0³2%,the optimal salt concentration for cell growth was5²0%. It was identified as H.elogata based on morphological and physio-biochemical characeristice as well as16s-rDNA sequence analysis.2The influencing factors on the azo dye degradation were explored. Degradationeffects in a series of salt concentrations were compared. In single factor experiments, theinfluencing factors of inoculation volume, initial azo dye concentration and pH weretested respectively under inoculation conditions of30℃and5%salinity. Theorthogonal experiments L9（33） were designed to obtain the optimal experimentconditions. Lastly, the degradation products were estimated by the UV-vis spectra. Theresults indicated that the strain H. elogata was tolerant to a wide salinity ranged from0 to32%,while the optimal salinity for its cell growth was from5to20%. Amongsalinity range of3to25%, the degradation rate increased initially and then decreasedwith the salinity increasing, and the best degradation effect happened when the salinitywas5%. At30℃and salinity of5%, the optimal conditions for degradation of azo dyeReactive Blue BRF were found as follows: initial concentration of100mg L^-1for azodye, pH7and initial inoculation volume of5%for the strain. Under these conditions,an88.62%degradation of azo dye was achieved over a time period of72hours. The UV-vis spectra revealed that the degradation products were quite different from ReactiveBlue BRF. There was no peak in visible region and UV absorption peaks in n-hexaneextracts, its dichloromethane extracts exhibited two UV absorption peaks, combinedwith mass spectrometry results, the degradation products were benzyl diamine,2,6-diamino-phenol and so on.3H. elogata could synthesize intracellular compatible solutes ectoine in thepresence of outside osmotic shock. Taking consideration of the factor salinity, theconcentration of monosodium glutamate and yeast extract content, the salinity was themost important factor. There existed strong interaction among salinity, monosodiumglutamate concentration of yeast extract concentration. The maximum ectoine was447mg L^-1, which obtained when the salinity, yeast extract concentration, monosodiumglutamate concentration was5%,0.5%,6%respectively.4The laboratory experiments that bacterial manure-Suaeda repaired the saline-alkali soil showed that Suaeda played role in promoting the increase of rhizospheremicroorganisms. There were an increasing trend in available nitrogen, availablepotassium and available phosphorusthere.