Lactococcus lactis

Khả năng ức chế vi khuẩn gây bệnh vibrio trong nước nuôi tôm của Bacillus subtilis HY1 và Lactococcus lactis CC4K

8p banhnamdua 25-07-2013 72 10   Download

CTP synthase catalyzes the reaction glutamine + UTP +ATPfiglutamate + CTP + ADP + Pi.The rate of the reaction is greatly enhanced by the allosteric activator GTP.We have studied the glutaminase half-reactionofCTP synthase from Lactococcus lactisand its response to the allosteric activator GTP and nucleotides that bind to the active site. In contrast to what has been found for the Escherichia colienzyme, GTP activation of the L. lactis enzyme did not result in similarkcat values for the glutami-nase activity and glutamine hydrolysis coupled to CTP synthesis. ...

8p research12 29-04-2013 44 2   Download

AcmA, the major autolysin ofLactococcus lactisMG1363 is a modular protein consisting of an N-terminal active site domain and a C-terminal peptidoglycan-binding domain. The active site domain is homologous to that of muramidase-2 of Enterococcus hirae, however, RP-HPLC analysis of muropeptides released fromBacillus subtilispeptidoglycan, after diges-tion with AcmA, shows that AcmA is an N-acetylglucosaminidase.

15p awards 06-04-2013 41 4   Download

In Lactococcus lactisthe enzymes phosphofructokinase (PFK), pyruvate kinase (PK) and lactate dehydrogenase (LDH) are uniquely encoded in the las operon. We used metabolic control analysis to study the role of this organization. Earlier studies have shown that, at wild-type levels, LDH has no control over glycolysis and growth rate, but high negative control over formate production (C Jformate LDH ¼
1:3).

12p awards 06-04-2013 33 3   Download

The cometabolism of citrate and glucose by growing Lactococcus lactisssp. lactis bv. diacetylactis was studied using a natural-abundance stable isotope technique. By a judicious choice of substrates differing slightly in their 13 C/ 12 C ratios, the simultaneous metabolism of citrate and glucose to a range of compounds was analysed. These end-products include lactate, acetate, formate, diacetyl and acetoin. All these products have pyruvate as a common intermediate.

9p awards 05-04-2013 44 3   Download

ThepyrGgene fromLactococcus lactisencodes CTP syn-thase (EC 6.4.3.2), an enzyme converting UTP to CTP. A series of strains were constructed with different levels of pyrGexpression by insertion of synthetic constitutive pro-moters with different strengths in front ofpyrG.These strains expressed pyrGlevels in a range from 3 to 665% relative to thewild-type expression level.Decreasing the level of CTP synthase to 43% had no effect on the growth rate, showing that the capacity of CTP synthase in the cell is in excess in a wild-type strain. ...

8p dell39 03-04-2013 45 5   Download

TheLactococcus lactisNRRL B-1821 prolidase gene was cloned and over-expressed in Escherichia coli. Under suboptimum growth conditions, recombinant soluble and active prolidase was produced; in contrast, inclu-sion bodies were formed under conditions preferred for cell growth.

10p media19 05-03-2013 44 2   Download

Lactococcus lactisFI9078, a construct carrying a disruption of theldh gene, converted approximately 90% of glucose into lactic acid, like the parental strain MG1363. This unexpected lactate dehydrogenase activity was puri-fied, andldhB was identified as the gene encoding this protein. The activa-tion of ldhB was explained by the insertion of an IS905-like element that created a hybrid promoter in the intergenic region upstream ofldhB.

13p media19 05-03-2013 36 3   Download

It has recently been shown that the Gram-negative bacterium Serratia marcescensproduces an accessory nonhydrolytic chitin-binding protein that acts in synergy with chitinases. This provided the first example of the pro-duction of dedicated helper proteins for the turnover of recalcitrant polysaccharides.

14p viettel02 22-02-2013 31 3   Download

Lactococcus lactiscan decrease the redox potential at pH 7 (Eh7) from 200 to )200 mV in oxygen free Man–Rogosa–Sharpe media. Neither the con-sumption of oxidizing compounds or the release of reducing compounds during lactic acid fermentation were involved in the decrease inEh7by the bacteria.

9p mobifone23 21-01-2013 44 3   Download

ATP and ADP inhibit, in varying degrees, several dehydrogenases of the central carbon metabolism of Lactococcus lactisATCC 19435in vitro, i.e. glyceraldehyde-3-phosphate dehydrogenase (GAPDH), lactate dehydroge-nase (LDH) and alcohol dehydrogenase (ADH). Here we demonstrate mixed inhibition for GAPDH and competitive inhibition for LDH and ADH by adenine nucleotides in single inhibition studies.

10p mobifone23 18-01-2013 43 4   Download

The acquisition of multidrug resistance in bacteria underlies the failure of antimicrobial therapy, and the emergence of pathogens that are resistant to almost the entire armoury of antibiotics.

10p cosis54 09-12-2012 38 1   Download

Tham khảo luận văn - đề án 'báo cáo khoa học: thu nhận bacteriocin bằng phương pháp lên men bởi tế bào lactococcus lactic cố định trên chất mang cellulose vi khuẩn (bc) và ứng dụng trong bảo quản thịt tươi sơ chế tối thiểu', luận văn - báo cáo, báo cáo khoa học phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả

10p nhatro75 22-07-2012 281 53   Download

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành y học dành cho các bạn tham khảo đề tài: Ascending cholangitis presenting with Lactococcus lactis cremoris bacteraemia: a case report

4p thulanh30 20-12-2011 37 3   Download

TÓM TẮT: Trong bài báo này, chúng tôi nghiên cứu việc cố định tế bào vi khuẩn Lactococcus lactis trên chất mang cellulose vi khuẩn (Bacterial Cellulose- BC) để ứng dụng lên men thu nhận bacteriocin và bảo quản thịt tươi sơ chế tối thiểu. Kết quả thu được như sau: - Hiệu quả sử dụng chế phẩm tế bào vi khuẩn cố định trên BC để lên men thu nhận bacteriocin khá cao: có thể tái sử dụng 9-10 lần mà vẫn đảm bảo về mặt...

10p heoxinhkute9 09-11-2010 334 98   Download