镇江香醋醋醅抑菌活性及机理的初步分析

【目的】评价镇江香醋醋酸发酵过程中醋醅及其主要酿醋功能微生物的抑菌活性。【方法】采用琼脂扩散法评价醋醅和功能微生物的抑菌效果,并考察加热、蛋白酶解、透析等不同处理对发酵液抑菌活性的影响。【结果】醋醅水提取液及4种酿醋功能微生物(Acetobacter pasteurianus、A.pomorum、Lactobacillus helveticus、L.plantarum)的发酵上清液对4种指示菌具有明显的生长抑制效果。发酵上清液中的抑菌活性物质具有一定耐热性和蛋白酶敏感性,分子量小于8 k D。【结论】镇江香醋醋醅及其所含醋酸杆菌和乳酸杆菌对环境微生物具有生长抑制活性,且抑菌活性物质的种类具有多样性。     

Long-term continuous evolution of acetate resistant Acetobacter aceti

Elevated concentrations of cytotoxic acetate are found in many environmental niches, and few species are relatively resistant to acetate. In particular the high-level acetate resistance of so-called acetic acid bacteria that occurs in industrial settings must be constantly selected for. To investigate the nature of such high-level resistance, we grew the moderately acetate-resistant Acetobacter aceti wild-type and acetate-sensitive Escherichia coli in long-term continuous cultures with increasing acetate concentrations at near neutral pH. While E. coli did not acquire any significant resistance after 125 generations of selection, A. aceti evolved the capability to grow at acetate concentrations exceeding 50 g/L within 240 generations. This phenotype was found to be stable for several generations in the absence of selective pressure, hence must be genetically determined. Intracellular acetate concentrations were significantly lower in evolved A. aceti, when compared to wild-type A. aceti and E. coli, indicating that cytoplasmatic anion accumulation is an important component of acetate toxicity.     

镇江地区上二叠统—下三叠统的牙形刺

详细描述了采自镇江附近１１－１，１１－２，７９－８号等钻孔的上二叠统—下三叠统的牙形刺化石共１１属２８种，建立了６个牙形刺化石带，其中上二叠统１个、下三叠统５个，并以牙形刺带为基础，进行了国内外对比。     

利用鲜醋糟酿制食醋的研究

鲜醋糟中含有相当数量的粗淀粉、粗蛋白、还原糖、纤维素等可供微生物生长的营养物质.本试验利用鲜醋糟作唯一填充料,入池淀粉控制在14—16%,采用“固态复式发酵法”酿醋,使糖化、酒化、醋化三个反应不分阶段,生产出了合格产品.发酵周期从原来的一个月缩短到12—13天,原料得以充分利用,从而降低了成本,提高了企业效益     

Bmo-miR-3377-5p down-regulates the Bombyx mori Sericin gene-1

MiRNAs are small non-coding molecules, which can regulate a huge number of genes. Based on bioinformatics analysis, we found a target site in the 3′UTR of BmSer-1 for binding bmo-miR-3377-5p. By using semi-quantitative RT-PCR, we detected that miR-3377-5p and BmSer-1 were both more highly expressed in the middle silk gland than in other tissues of 3-day-old fifth-instar Bombyx mori larvae, implying that there is a spatiotemporal condition for miR-3377-5p regulating on BmSer-1. To confirm this prediction, a BmSer-13′UTR recombinant luciferase reporter pGL3.0 [A3-luc-BmSer-1-3′UTR-SV40] and pri-bmo-miR-3377-5p expression pcDNA3.0 [ie1-egfp-pri-bmo-miR-3377-5p-SV40] were constructed and co-transfected into B. mori ovary cells (BmN cells). The results showed that miR-3377-5p suppressed the expression of BmSer-1 significantly (P < .001). When BmN cells were co-transfected by an artificial inhibitor together with a miR-3377-5p expression vector and a BmSer-1-3′UTR recombinant plasmid, BmSer-1 expression increased significantly (P < .05), indicating that the inhibitor was active against miR-3377-5p, and expression of BmSer-1 was recovered. Moreover, we injected miR-3377-5p expression plasmid and bmo-miR-3377-5p inhibitor into 3-day-old fifth-instar larvae. At 36 h post-injection, silk glands were collected for total RNA extraction. Quantitative RT-PCR analysis showed that miR-3377-5p down-regulated the expression of BmSer-1 in vivo, while there was no significant difference inhibitor treatment group compared with NC. Thus, we conclude that miR-3377-5p down-regulated the expression of BmSer-1. Our results provide insight for understanding the function of miRNAs and the regulation network of silk protein genes.     

功能性双歧醋营养成分分析及保质期观察

目的分析双歧醋的营养成分及保质期观察。方法采用现代多种营养成分分析方法对双歧醋进行主要营养成分的分析测定。结果双歧醋营养丰富,含有多种微量元素,含有18种氨基酸,其中8种人体必需氨基酸含量占总量的42.5%,富含醋酸、乳酸等8种有机酸成分。结论双歧醋营养成分丰富,保质期长,作为一种功能性醋产品值得推广应用。     

山西醋醅中醋酸菌的分离及初步鉴定

目的从山西省某醋厂能正常发酵的醋醅中分离出优势醋酸菌株并加以鉴定。方法经过菌种的增殖培养,采用稀释涂布法分离菌株,得到127株醋酸菌,再经过初筛和复筛,筛选出9株产醋酸优势菌株,对9株优势菌株进行传代培养。结果筛选出在传代培养过程中,产醋酸酸度高且产量稳定的菌株为L4,其产酸量为66.92 g/L,酒精转化率为72.42%。结论根据菌株L4形态观察及生理生化特征初步判定为醋酸菌属醋化醋杆菌奥尔兰亚种。     

镇江香醋核心酿造微生物醋酸杆菌和乳酸杆菌共培养对生长代谢的影响

[目的]研究镇江香醋酿造过程核心功能微生物醋酸杆菌属与乳酸杆菌属菌株之间的相互作用关系.[方法]本文以分离到的镇江香醋酿造中的核心微生物2株醋酸杆菌和8株孔酸杆菌为研究对象,构建醋酸杆菌和乳酸杆菌共培养发酵体系,比较异位与原位条件下,纯培养及共培养中菌株的生长和代谢(包括还原糖、乙醇和总酸等含量)差异;采用GC-MS检...     

双歧醋对高脂饮食大鼠血脂影响的机制探讨

目的 探讨双歧醋对高脂饮食大鼠血脂的影响机制.方法 48只SD大鼠被随机分成双歧醋低剂量组[1.8 mL/(kg·BW)]、中剂量组[3.4 mL/(kg· BW)]、高剂量组[6.8 mL/(kg·BW)]和市售醋组[3.4 mL/(kg·BW)]、高脂模型组以及基础对照组,观察双歧醋对高脂饮食大鼠血脂的影响作用机制,测定指标包括大鼠肝脏脂质、大鼠LDLR的免疫组化分析,HMGCoA还原酶和LDLR的RT-PCR分析.结果 双歧醋各组对于HMGCoA还原酶表达有抑制作用,但可以上调LDLR的基因和蛋白质表达.结论 双歧醋可以通过调节HMGCoA还原酶和LDLR的表达预防高脂饮食大鼠高血脂的发生.