Study On Screening And Identification For Agarase-Producing Marine Bacteria And Optimization Of Its Fermentation Conditions

Agar is the water-soluble polysaccharide with extracted from Gelidium amansii. The main ingredients are agarose and agaropectin. It has great application prospects in food, medicine, clinic and biochemistry area. And in view of its gelling properties, it is widespread use of laboratory cluture. Agarase can hydrolyze polysaccharide and it is a kind of seaweed tool enzyme,meanwhile has important value in single cell separation and enzymatic degraded cell wall into making protoplasm.Also, agarase in molecular biology there are also many aspects of applications. Studies of agarase-producing strains have theoretical significance and application value.From dalian coastal waters Gelidium screened relative higher enzyme activity of agarase-producing strains. And through the morphological characteristics, physiological and biochemical characteristics and 16SrDNA gene sequence analysis and study its classification status. The strain (named ZGR-26) is Gram negative bacilli. It has 99% homology to Vibrio agarivorans,both physiological and biochemical characteristics consistent, can be determined primarily for Vibrio agarivorans.By the test of single factor and orthogonal test, the optimum ferment conditions an agar-degrading marine bacterium Vibrio agarivorans were determined as follows:Peptone 4.0 g/L, yeast extract 1.5 g IL, agarl.5 g/L,12% inoculating quantity, rate of shaking flask with 40 mL liquid in a 100 mL flask was 150 r/min. After 48 h fermentation at 25℃ Incubated in the optimum conditions, the highest agarase activity was found.Under the best components of medium and culture condition, the activity of chitosanase was up to 108.2 U/mL which was 3 times higher than that under the original conditions.