• Korean Journal of Soil Science and Fertilizer
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• v.38 no.5
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• pp.287-293
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• 2005

In this work, to develop soil inoculant which maintains stable viable cells and normalized quality, studies on micro-encapsulation with bacteria and yeast cells were performed by investigating materials and methods for micro-encapsulation as well as variation and stability of encapsulated cells. Preparation of capsule was conducted by application of extrusion system using micro-nozzle and peristaltic pump. K-carragenan and Na-alginate were selected as best carrier for gelation among K-carageenan, Na-alginate, locust bean gum, cellulose acetate phthalate (CAP), chitosan and gelatin tested. Comparing the gels prepared with Bacillus sp. KSIA-9 and carriers of 1.5% concentration, although viable cell of K-carragenan and Na-alginate was six times higher than those of other, Na-alginate was finally selected as carrier for gelation because it is seven times cheaper than K-carragenan. The gel of 1.5% Na-alginate was also observed to have the best morphology with circular hardness polymatrix and highest viable cell. When investigating the stability of encapsulated cells and the stabilizer effect, free cells were almost dead within 30 or 40 days whereas encapsulated cells decreased in 10% after 30 days and 15-30% even after 120 days. As stabilizer for maintaining viable cell, both 1% starch and zeolite appeared to possess the level of 70-80% cell for bacteria and yeast until after 120 days.