Van-Thuoc Doan, Huu-Phong Tran, Minh-Khuong Dang, Hatti-Kaul Rajni
Department of Microbiology and Biotechnology, Faculty of Biology, Hanoi National University of Education, 136 XuanThuy, CauGiay, Hanoi, Vietnam.
Appl Biochem Biotechnol. 2015 Mar;175(6):3120-32. doi: 10.1007/s12010-015-1479-4. Epub 2015 Jan 21.
Yangia sp. ND199, a moderate halophile isolated from mangrove soil sample in Vietnam, was found to accumulate poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) from unrelated carbon sources in a medium with 4.5% (w/v) NaCl. Cultivation with glycerol as carbon source and yeast extract as nitrogen source resulted in maximum cell dry weight of 5.7 g/l and PHBV content of 52.8 wt% (containing 2.9 mol% of 3HV) after 40 h. The 3HV content of the PHBV was the highest during initial stages of copolymer production and decreased with increase in the copolymer amount with time, but was not affected by changing the pH of the culture medium. Only homopolymer poly(3-hydroxybutyrate) was synthesized when monosodium glutamate was used as the nitrogen source. Fed-batch cultivation of Yangia sp. ND199 with glycerol and yeast extract gave PHBV content and productivity of 53.2 wt% and 0.44 g/l/h, respectively, which were reduced to 40.6 wt% and 0.25 g/l/h, respectively, with crude glycerol as carbon source. Both the copolymer content and productivity were improved to 56 wt% and 0.61 g/l/h, respectively, by using 1:1 mixture of crude glycerol and high fructose corn syrup. This is the first report of PHBV production by a wild-type halophilic bacterium using glycerol as carbon source.
Yangia sp. ND199是从越南红树林土壤样本中分离出的一种中度嗜盐菌，发现在含有4.5%（w/v）氯化钠的培养基中，它能从无关碳源积累聚（3-羟基丁酸酯-co-3-羟基戊酸酯）（PHBV）。以甘油为碳源、酵母提取物为氮源进行培养，40小时后细胞干重最大可达5.7 g/l，PHBV含量为52.8 wt%（含2.9 mol%的3HV）。PHBV的3HV含量在共聚物生产初期最高，随共聚物量随时间增加而降低，但不受培养基pH值变化的影响。当使用谷氨酸钠作为氮源时，仅合成了均聚物聚（3-羟基丁酸酯）。对Yangia sp. ND199进行甘油和酵母提取物的分批补料培养，PHBV含量和生产率分别为53.2 wt%和0.44 g/l/h，而以粗甘油为碳源时，分别降至40.6 wt%和0.25 g/l/h。通过使用粗甘油和高果糖玉米糖浆的1:1混合物，共聚物含量和生产率分别提高到56 wt%和0.61 g/l/h。这是关于野生型嗜盐细菌利用甘油作为碳源生产PHBV的首次报道。
