食品科学 ›› 2021, Vol. 42 ›› Issue (20): 75-82.doi: 10.7506/spkx1002-6630-20200922-279

• 生物工程 • 上一篇    下一篇

云南牟定酸浆水中优势产酸菌的分离鉴定及生长特性

张宸瑞,薛桥丽,白彬阳,胡永金   

  1. (1.云南农业大学食品科学技术学院,云南 昆明 650201;2.云南农业大学学报编辑部,云南 昆明 650201)
  • 出版日期:2021-10-25 发布日期:2021-11-12
  • 基金资助:
    云南省科技创新强省专项(2016AB016)

Isolation, Identification and Growth Characteristics of Dominant Acid-Producing Bacteria from Fermented Soy Whey from Sufu Production in Mouding, Yunnan

ZHANG Chenrui, XUE Qiaoli, BAI Binyang, HU Yongjin   

  1. (1. College of Food Science and Technology, Yunnan Agricultural University, Kunming 650201, China; 2. Editorial Department of Journal of Yunnan Agricultural University, Kunming 650201, China)
  • Online:2021-10-25 Published:2021-11-12

摘要: 为挖掘自然发酵酸浆水中的优势核心产酸菌,分别从云南牟定两家腐乳生产企业自然发酵酸浆水中分离筛选到10 株产酸菌株,对其进行形态学观察、生理生化鉴定及16S rDNA测序分析,并对产酸较高的菌株进行生长性能分析。结果表明:云南牟定A公司生产腐乳的酸浆水中优势菌株分别为Lactobacillus fermentum(YQZ1)、Lactococcus raffinolactis(YQZ2)、Lactobacillus plantarum(YQZ3)、Enterococcus casseliflavus(YQZ4)、Microbacterium oxydans(YQZ5);云南牟定B公司生产腐乳的酸浆水中优势菌株分别为Enterococcus faecium(XJZ1)、L. plantarum(XJZ2)、Lactobacillus paracasei(XJZ3)、Enterococcus hirae(XJZ4)、L. paracasei(XJZ5)。对分离到菌株的生长温度、生长曲线、产酸能力、耐酸能力、耐渗透压能力进行分析比较。XJZ4最适生长温度为32 ℃,其余菌株、自然菌群的最适生长温度均为37 ℃。菌株XJZ2生长速率最快,菌株YQZ1、XJZ2繁殖能力最强。菌株YQZ1、XJZ2产酸能力最强,有机酸累积量最多,48 h产酸量分别高达43.61、50.91 g/L。菌株YQZ3、YQZ5的耐酸性最强,菌株YQZ1、XJZ2耐酸性良好。菌株YQZ4在NaCl质量浓度为4 g/100 mL时仍能保持菌体浓度(OD600 nm)为1.53,其余菌株在NaCl质量浓度大于4 g/100 mL时生长受到明显抑制。菌株YQZ1、XJZ2具有较强的繁殖和产酸性能,用其混合菌种制备黄浆水,可缩短工艺周期、提升酸浆豆腐品质。

关键词: 酸浆水;产酸菌株;筛选;鉴定;生长特性

Abstract: Totally 10 acid-producing strains were isolated from naturally fermented soy whey (Suanjiangshui) collected from two fermented tofu (sufu) producers in Mouding, Yunnan. The strains were identified by morphological observation, physiological and biochemical identification and 16S rDNA sequence analysis, and their growth characteristics were evaluated. The results showed that Lactobacillus fermentum (YQZ1), Lactococcus raffinolactis (YQZ2), Lactobacillus plantarum (YQZ3), Enterococcus casseliflavus (YQZ4), and Microbacterium oxydans (YQZ5) were the dominant strains in one sample, while Enterococcus faecium (XJZ1), L. plantarum (XJZ2), Lactobacillus paracasei (XJZ3), Enterococcus hirae (XJZ4), and L. paracasei (XJZ5) were the dominant strains in the other. The optimal growth temperature was 32 ℃ for strain XJZ4 and 37 ℃ for the other strains and the natural microflora. Strain XJZ2 had the fastest growth rate, and YQZ1 and XJZ2 had the strongest reproductive ability. YQZ1 and XJZ2 had the strongest acid-producing capacity and the largest accumulation of organic acid, giving acid yield of 43.61 and 50.91 g/L after 48 h, respectively. YQZ3 and YQZ5 had the strongest acid tolerance, followed by YQZ1 and XJZ2. The optical density at 600 nm (OD600 nm) for the cell density of YQZ4 was maintained at 1.53 in the presence of 4 g/100 mL NaCl, whereas the growth of the other strains was inhibited by NaCl concentrations of greater than 4 g/100 mL. It is concluded that the strains YQZ1 and XJZ2 had strong reproductive ability and high acid-producing ability, making their mixed cultures promising candidates to be used in the preparation of Suanjiangshui for shortened fermentation period and improved quality of fermented tofu.

Key words: fermented soy whey; acid-producing bacteria; screening; identification; growth characteristics

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