Isolation, Culture And Antifouling Activity Test Of Marine Bacteria Which Can Produce Protease

Marine microorganisms has became biology and antifouling engineeringresearch hotspot due to its various kinds, widely distributed and can generate a varietyof active substance which different from the terrestrial animal. The screening ofMarine microorganisms and determination of their metabolites activity is one of thekey factors for their successful application in the ship antifouling field. Protease canbe used as a well enzyme preparation, for being obtaining easily (some enzyme hasbeen produced by industry), biodegradable and environment friendly, low toxicity andso on. As the development of biotechnology in the ship antifouling field, proteaseantifouling has got more attention.In this paper the sea water from Kiaochow Bay was used as raw material. Andseparate out the protease-producing strain by streak plate method and breeding byultraviolet irradiating mutagenesis; To examine the carbon and nitrogen sources forthe influence of the enzyme activity by changing the components of the culturemedium; and find out the best culture condition through the changes of the variousenvironmental parameters. In this paper we also investigated the antifouling activityof the crude enzyme extract by Mytilus edulis, Navicula, Balanus albicostatus cyprid,SRB and so on.The best culture medium of this protease strains were screened through a seriesof optimization of the culture medium. Corn starch powder0.5g; Potassiumdehydrogenate phosphate:0.36g; Disodium hydrogen phosphate:1.3g; Seven waterzinc sulfate:0.02g; Seven hydrated calcium chloride:0.002g; Casein hydrolysateamino acids:0.05g；sea water1L.On the basis of understanding the nature of the protease enzyme activitycomprehensively. We can improve the protease enzyme activity and use it in the shipantifouling. In order to fully understand the influence of parameters changes toprotease enzyme activity, in addition to the culture medium components, in this paper other parameters were also studied. Including pH value, environmental factors such astraining time on the influence of protease activity. The results indicated that theprotease enzyme activity significantly influenced by pH value, with pH value from6to8.5, protease activity first increased and then drop. In the pH of7protease activityreaches maximum; Determinated enzyme activity from1to5days, monitoring themaximum enzyme activity is in the second day.In this artistical, all the four kinds ofmetal ions (Calcium, potassium, magnesium, manganese) can inhibit the activity ofthe protease. But the inhibition of the copper is not obvious.Due to the low salinitylevel cannot sustain Marine bacteria growth required osmotic pressure, in this chapter,with lower salinity, protease activity declined.We deceived the antifouling activity of the protease by mussel, barnacle, SRBand so on. Compared with the control, the experimental group had well antifoulingactivity and inhibited these fouling organisms adhesion on the based material.Thetoxicity test to mussel and barnacle showed that:When put the barnacle and mussel inthe raw sea water, these fouling organisms adhesion was similar to the without controltest. This further proof that protease had well antifouling activity and nontoxic andenvironmental protection, It is a kind of environmental friendly antifouling agent.B. amphitrite is considered to be a serious pest because of its rapidly breed, shortreproductive cycle and is widespread throughout the subtropics. On the other hand,Cyprids attached to ship material surface and underwater engineering through itssecretion of colloidal material. not only affect the normal use of equipment, but wouldcause severe economic losses. Therefore, It is also conducive to laboratory testing ofexperimental antifoulants. Researching the adhere print of B. amphitrite is useful ofthe development of new materials and antifouling surfactant. So we researched theattached print by using cellulose acetate membrane and glass as base material. Whichprovide theoretical basis for the development of new types of antifouling agent.To sum up, This paper probed into the antifouling mechanism of Marine proteaseby separating Marine microbial proteinase produced bacteria. Studied theenvironment factor which can influence the enzyme activity, and did the antifoulingactivity test and toxicity test of the protease.The result indicated that the protease is non-toxic, environmental protection, with excellent antifouling activity.