Research On Production Technology Of Gellan Gum

Based on the high efficiency, nontoxicity and thermostability gellan gum a new microbialextracellular polysaccharide obtained from fermentation product is widely used in food,medicine and chemical industry, etc. At present, the production rate of gellan gum is not high,its production and application will be great prospects for development in the future, so as itwill be research direction of many researchers’. Commonly used production strains of gellangum is a kind of aerobic gram-negative bacilli, it can put the glucose, maltose and starch ascarbon source, and use beef paste, peptone, bean cake powder as nitrogen source, then addother inorganic salts in to content the fermentation production. Research will be divided intothree parts, the content is as follows.Viscosity of fermentation medium and gum productive rate is settled as the parameters inthis experiment, Fermentation parameters such as Fermentation time, seed age, loaded liquid,inoculum size, culture temperature, pH, rotation speed were optimized through single factoroptimization. By using orthogonal experimental design, it was ultimately determined theoptimum fermentation conditions as follow: fermentation time was60h; seed age was20h;loaded liquid was10%; inoculum size was1％;culture temperature was30℃; pH was7.0;rotation speed was220rpm.Glucose, maltose, sucrose,2%soluble starch and lactose were regard as the carbon sourcerespectively, other ingredients was the same, it was concluded that the best carbon source wassucrose, and then it was determined the best dosage was3％by single factor experiment;beef extract peptone, yeast extract, soybean cake powder, and ammonium nitrate were regardas nitrogen source respectively, other ingredients was not change, it was concluded that thebest nitrogen source was soybean cake powder, then it was determined the best dosage bysingle factor experiment; MgSO4, KH2PO4, NaCl, KCl, MnCl2, FeSO4were regard asinorganic salt respectively, other ingredients was the same, the results showed MgSO4andKH2PO4both Can be very good as inorganic salt, then it was determined the best dosage bysingle factor experiment; finally it was determined the the best composition of the medium through the orthogonal experiment: sucrose was3%, bean cake powder is0.6%, MgSO4was0.06%, KH2PO4was0.14%It was found the best combination of carbon sources from Two-step adding method wasthat3%of the initial carbon source; supplemented with1.5%carbon source, The best time foradding carbon was16h. The best combination type of pH was determined adjust and controlthe pH to7.0every4hours. It was determined the the best composition of the mediumthrough the orthogonal experiment: Supplementary carbon was1.5％,the time of addingcarbon source was16h, fixed pH was7.0. Viscosity of fermentation broth and rat of gellangum reached45600cp and1.62respectively in this condition, the rat of gellan gum increased15.7％.