碩士 / 國立中興大學 / 植物病理學系所 / 97 / Pseudomonas putida YLFP14 has been used to control the bacterial spot of sweet pepper caused by Xanthomonas axonopodis pv. vesicatoria and Xanthomonas vesicatoria. For mass production, YLFP14 was incubated in fermenter containing molasses, yeast powder and soybean powder (MYS) as substrates in previous studies. In order to prolong the storage life of YLFP14 at room temperature (25℃), the objectives of this study are to develop of medium formula for mass production and alginate encapsulation technique of YLFP14. The preliminary results revealed that reagent-grade yeast extract and glucose were the best nutrient sources for growth of YLFP14. Industry-grade materials with similar compositions of yeast extract and glucose, yeast powder and industrial glucose, were further tested for fermentation of YLFP14. The number of YLFP14 in yeast powder broth was higher than that in MYS. Supplementation of 0.1% to 0.9% industrial glucose to the broth had no effect on the growth of YLFP14. An alginate encapsulation technique for storage of YLFP14 was developed. The antagonistic and disease-controlling activity of YLFP14 after encapsulated in alginate beads were not affected. To examine the storage life of YLFP14 in alginate beads, a spontaneous rifampicin resistance mutant, YFLP14r, was selected. YLFP14r in alginate beads can maintain at 108 colony forming unit (CFU) per gram after storage for 21 weeks at 25℃ while its initial bacterial number was at 1010 CFU/g . The results showed that alginate bead is more suitable for storage of YLFP14r than in fermentation broth. Factors affecting the survival of YLFP14r in alginate beads were investigated. The survival of YLFP14r in alginate beads prepared from stationary phase was better than cells from log phase. The survival of YLFP14r suspended in fermentation broth was better than that suspended in distilled water. There was no significant difference in antagonistic activity between YLFP14r from dissolved alginate beads stored for 21 weeks and from fresh fermenter product. However, decreased antagonistic efficiency was observed in the individuals of YLFP14r population stored in fermentation broth. Thus, alginate encapsulation can not only effectively maintain the population but also the antagonistic efficiency of YLFP14r after long-term storage at room temperature.
| Identifer | oai:union.ndltd.org:TW/097NCHU5363015 |
| Creators | Cheng Tan, 譚錚 |
| Contributors | Kuo-Ching Tzeng, 曾國欽 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 50 |
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