解淀粉芽孢杆菌KN-BL-1及其发酵豆粕产抗菌肽类物质的研究

以牛津杯法比较解淀粉芽孢杆菌KN-BL-1及其发酵豆粕的抑菌效果,通过酸沉淀法分离粗多肽,确定产生抑菌效果的为多肽类物质,通过DEAE-Sepharose离子交换层析及Sephadex G-25凝胶过滤层析分离纯化粗多肽以研究其各组分的抑菌效果,并使用4000 Q TRAP液相色谱-质谱联用仪初步确定抗菌肽样品的分子量范围.结果表明,KN-BL-1及其发酵豆粕浸提液对S.aureus等革兰氏阳性菌均有明显的抑菌效果;粗多肽经过层析分离纯化后,三个峰表现抑菌特性,其中有一个抑菌效果最好,抑菌圈清晰,直径为19.8 mm.     

Microbial Diversity in Ngari,Hentak and Tungtap,Fermented Fish Products of North-East India

Ngari, hentak and tungtap are traditional fermented fish products of North-East India. Eighteen samples of ngari, hentak and tungtap were collected and were analysed for microbial load. Lactic acid bacteria, endospore-forming rods, yeasts and aerobic mesophilic counts ranged from 4.0 to 7.2, 3.3–4.6, <1–3.5 and 4.3–7.3 log c.f.u./g, respectively. Lactic acid bacteria were identified as Lactococcus lactis subsp. cremoris, Lactococcus plantarum, Enterococcus faecium, Lactobacillus fructosus, Lactobacillus amylophilus, Lactobacillus coryniformis subsp. torquens and Lactobacillus plantarum. Endospore-forming rods were identified as Bacillus subtilis and Bacillus pumilus, aerobic coccal strains were identified as Micrococcus. Yeasts were identified as species of Candida and Saccharomycopsis. Pathogenic contaminants were detected in all samples, however, none of the sample contained more than 10² c.f.u./g of Bacillus cereus, 10³ c.f.u./g of Staphylococcus aureus and enterobacteriaceae population, respectively. Enzymatic and antimicrobial activities of the isolates were tested. None of the strains produced biogenic amines in the method applied. Most strains of LAB had a high degree of hydrophobicity, indicating their ‘probiotic’ characters. This study has demonstrated the microbial diversity within the species of lactic acid bacteria, Bacillus and yeasts. This revised version was published online in July 2006 with corrections to the Cover Date.     

Improvement in the quality of a fermented seaweed beverage using an antiyeast starter of <Emphasis Type="Italic">Lactobacillus plantarum</Emphasis> DW3 and partial sterilization

The quality of a fermented beverage (FSB) produced from seaweed (Gracilaria fisheri) was investigated after four different fermentation processes. 1, a normal fermentation as control (N-N); 2, batch with addition of an inoculum of an antiyeast starter culture, Lactobacillus plantarum DW3 (N-S); 3, a partial sterilization of the seaweed with 0.5% potassium metabisulfite (KMS) (P-N); and 4, a partial sterilization followed by an inoculum as for 2 (P-S). At the end of fermentation (60 days) and after storage for 3 months, all treatment sets passed the microbiological quality guidelines, as no bacterial indicators (total coliforms and Escherichia coli) or foodborne pathogens (Salmonella sp. Clostridium perfringens and Staphylococcus aureus) were detected. All treatments improved the availability of elements (Cu, Zn, and Fe) in the seaweed beverage and they were all below the recommended safety levels. Toxic compounds such as methanol, and the elements As and Pb were below either the detection or safety limits. The starter culture controlled yeast contamination and had inhibitory effects against foodborne pathogenic bacteria (Vibrio parahaemolyticus PSSCMI 0064 > Bacillus cereus ATCC 11778 > Salmonella typhi PSSCMI 0034 ∼ Staphylococcus aureus PSSCMI 0004 ∼ E. coli PSSCMI 0001). The inoculation set without pretreatment by KMS (N-S) was the treatment that produced the best FSB based on its antibacterial activity, reduction of contaminated yeasts, remaining probiotic LAB and organoleptic properties.     

Production of phenyllactic acid by lactic acid bacteria: an approach to the selection of strains contributing to food quality and preservation

The ability of lactic acid bacteria (LAB) to produce phenyllactic (PLA) and 4-hydroxy-phenyllactic (OH-PLA) acids, metabolites involved in food quality and preservation, has been evaluated by HPLC analysis in 29 LAB strains belonging to 12 species widely used in the production of fermented foods. Metabolite production was demonstrated for all strains of the species Lactobacillus plantarum, Lactobacillus alimentarius, Lactobacillus rhamnosus, Lactobacillus sanfranciscensis, Lactobacillus hilgardii, Leuconostoc citreum, and for some strains of Lactobacillus brevis, Lactobacillus acidophilus and Leuconostoc mesenteroides subsp. mesenteroides. Strains were distinguished by analysis of variance in three groups including 15 strains that produced both metabolites (0.16-0.46 mM PLA and 0.07-0.29 mM OH-PLA), five strains accumulating in culture only PLA (0.17-0.57 mM) and nine non-producer strains (< or = 0.10 mM PLA and < or = 0.02 mM OH-PLA). Improvement of phenyllactic acid production was obtained in a selected L. plantarum strain by increasing the concentration of phenylalanine in culture and using low amounts of tyrosine.     

侗族传统发酵肉的微生物特性

目的：对侗族传统发酵肉的微生物生态系的构成进行分析。方法：稀释平板法,结果：乳酸细菌在发酵30d达到最大值,4个处理的logCFU/g值均在8.2以上;280个MRS平板分离物中,米酒乳杆菌占37.91%,片球菌占20.71%。MSA平板培养物在发酵全过程中,均呈上升趋势;60d后,4个处理的logCFU/g值平均为5.5,增加了2.0;腐生葡萄球菌、肉葡萄球菌和木糖葡萄球菌是其优势菌群。酵母菌的数量在发酵过程中未见明显增加,发酵完毕,菌数的logCFU/g值在5.7左右,鉴定结果表明主要是德巴利酵母和球拟酵母。革兰阴性的肠细菌群发酵50d后,其logCFU/g值在2.0以下,结论：对发酵肉品微生态系的不断了解和肉品发酵技术不断完善,将为人们提供新颖、营养、安全的食品。     

微生物发酵四君子汤制剂对荷瘤小鼠抗氧化功能的影响

目的探讨微生物发酵四君子汤制剂(FSJZD)对荷瘤小鼠抗氧化能力的影响。方法通过建立小鼠S180肿瘤模型,分别采用黄嘌呤法、硫代巴比妥酸法、硝酸还原酶法检测血清中的超氧化物歧化酶(SOD)、丙二醛(MDA)和一氧化氮(NO)含量,研究FSJZD的抗氧化能力。结果 FSJZD可显著升高荷瘤小鼠及CTX治疗荷瘤小鼠所致免疫抑制模型血清中的SOD水平,明显降低CTX所致免疫抑制小鼠血清中NO和MDA含量。结论 FSJZD能够显著提高荷瘤机体的抗氧化能力、降低化疗对机体产生的危害作用。     

Video Sequence-Based Iris Recognition Inspired by Human Cognition Manner

In video sequence-based iris recognition system, the problem of making full use of relationship and correlation among frames still remains to be solved. A brand new template level multimodal fusion algorithm inspired by human cognition manner is proposed. In that a non-isolated geometrical manifold, named Hyper Sausage Chain due to its sausage shape, is trained using the frames from a pattern class for representing an iris class in feature space. We can classify any input iris by observing which manifold it locates in. This process is closer to the function of human being, which takes ＇matter cognition＇ instead of ＇matter classification＇ as its basic principle. The experiments on self-developed JLUBR-IRIS dataset with several video sequences per person demonstrate the effectiveness and usability of the proposed algorithm for video sequence-based iris recognition. Fur- thermore, the comparative experiments on public CASIA-I and CASIA-V4-Interval datasets show that our method can also achieve improved performance of image-based iris recognition system, provided enough samples are involved in training stage.     

Selection criteria for lactic acid bacteria to be used as starter cultures for various food commodities

Abstract: Lactic acid bacteria (LAB) are the most important bacteria used in food fermentations. Apart from general demands for starter cultures from the view of safety, technological effectiveness and economics, numerous specific aspects have to be considered when selecting strains for the different food fermentations. Therefore selection criteria for LAB depend on the type and the desired characteristics of the final product, the desired metabolic activities, the characteristics of the raw materials and the applied technology. Special selection criteria for LAB for use in the fermentation of sausages and vegetables as well as for the malolactic fermentation in wine are discussed.     

鄂尔多斯地区自然发酵苦菜中优良特性乳酸菌的筛选

【背景】鄂尔多斯地区传统自然发酵苦菜风味和作用独特,但目前尚无关于发酵苦菜中乳酸菌种类及其生物学特性研究的报道。【目的】获得适用于工业化生产特性优良的乳酸菌。【方法】通过测定总酸度筛选高产酸菌株,并进行形态学鉴定、生理生化特性研究,以及16S rRNA基因片段分析。【结果】经鉴定5株高产酸的菌株均为植物乳杆菌,生长温度范围宽,并且具有耐酸、耐碱、耐盐、耐热的特性。【结论】试验菌株具有优良的生理特性和潜在的益生特性,可用于食品工业的生产。     

发酵灵芝菌粉抑制小鼠肿瘤及对正常小鼠免疫功能影响的研究

研究了发酵灵芝菌粉对接种S-180瘤细胞后的实验小鼠肿瘤的抑制作用、发酵灵芝菌粉对正常的实验小鼠腹腔巨噬细胞吞噬能力以及脾脏自然杀伤细胞活性的影响,结果表明发酵灵芝菌粉对小鼠移植性肿瘤的生长有明显的抑制作用,但对正常小鼠腹腔巨噬细胞吞噬能力以及脾脏自然杀伤细胞的活性无明显的免疫促进作用。