Ester‐synthesis mechanism and activity by Bacillus licheniformis , Candida etchellsii and Zygosaccharomyces rouxii isolated from Chinese horse bean‐chili‐paste

Author(s):  
Linzi Yang ◽  
Xueli Li ◽  
Yunhao Lu ◽  
Yuanping Lv ◽  
Yuanlong Chi ◽  
...  
Author(s):  
B.K. Ghosh

Periplasm of bacteria is the space outside the permeability barrier of plasma membrane but enclosed by the cell wall. The contents of this special milieu exterior could be regulated by the plasma membrane from the internal, and by the cell wall from the external environment of the cell. Unlike the gram-negative organism, the presence of this space in gram-positive bacteria is still controversial because it cannot be clearly demonstrated. We have shown the importance of some periplasmic bodies in the secretion of penicillinase from Bacillus licheniformis.In negatively stained specimens prepared by a modified technique (Figs. 1 and 2), periplasmic space (PS) contained two kinds of structures: (i) fibrils (F, 100 Å) running perpendicular to the cell wall from the protoplast and (ii) an array of vesicles of various sizes (V), which seem to have evaginated from the protoplast.


Author(s):  
Xiaorong Zhu ◽  
Richard McVeigh ◽  
Bijan K. Ghosh

A mutant of Bacillus licheniformis 749/C, NM 105 exhibits some notable properties, e.g., arrest of alkaline phosphatase secretion and overexpression and hypersecretion of RS protein. Although RS is known to be widely distributed in many microbes, it is rarely found, with a few exceptions, in laboratory cultures of microorganisms. RS protein is a structural protein and has the unusual properties to form aggregate. This characteristic may have been responsible for the self assembly of RS into regular tetragonal structures. Another uncommon characteristic of RS is that enhanced synthesis and secretion which occurs when the cells cease to grow. Assembled RS protein with a tetragonal structure is not seen inside cells at any stage of cell growth including cells in the stationary phase of growth. Gel electrophoresis of the culture supernatant shows a very large amount of RS protein in the stationary culture of the B. licheniformis. It seems, Therefore, that the RS protein is cotranslationally secreted and self assembled on the envelope surface.


2018 ◽  
Vol 7 (3) ◽  
Author(s):  
Budiasih Wahyuntari., dkk

Isolate I-5 was isolated from Ciseeng hot spring, West Java and was identified as Bacillus licheniformis I-5. The isolate produces extracellular xylanolytic enzymes on Oatspelt containing Luria broth agar medium. Optimal activity of the crude enzyme was  observed at 50ºC and pH 7. The effect of sodium dodecyl sulphate, b-mercaptoethanol and Triton-X100 were observed. Incubating the crude enzyme in 1.5% SDS and 1.5% b-mercaptoethanol at 50oC for 90 minutes then adding Triton-X100 at final concentration of 3.5% for 45 minutes only reduced 5.75% of the initial enzyme activity. SDS/PAGE and zymogram analysis showed that at least two xylanolytic enzymes presence in the crude enzyme. The molecular weight of the enzyme was estimated about 127 and 20kD. The enzyme hydrolysed xylan into xylobiose, xylotriose and other longer xylooligosaccharides. Thermal stability of the crude enzyme was observed at 50, 60, and 70oC and pH 7 and 8. The results showed that the half time of the crude enzyme incubated at 50, 60, and 70oC pH 7 was 2 hours 55 minutes; 2 hours 33 minutes and 1 hour 15 minutes respectively. The half time at 50, 60 and 70oC, pH 8 was 2 hours 48 minutes; 1 hour 22 minutes and 1 hour 9 minutes respectively.keywords: Xilanase, Bacillus licheniformis I-5, thermal stability


Author(s):  
O. Merzlyakova ◽  
V. Rogachyev ◽  
V. Chegodaev

The efficiency of introducing probiotics based on strains of Bacillus subtilis, Bacillus licheniformis and their consortium in the amount of 150 g/t of feed into the diets of laying quails has been studied. The experiment lasting 182 days has been carried out on four groups of quails with 30 heads in each. The quails have been housed in the broiler battery in compliance with the required microclimate conditions. Quails of all groups have been received the main diet (compound feed) developed taking into account their age and physiological characteristics. The quails of the 1st, 2nd and 3rd experimental groups in addition to the main diet received probiotics (150 g/t compound feed) based on strains Bacillus subtilis, Bacillus licheniformis and their consortium, respectively. It has been found that feeding the laying quails of the consortium of strains Bacillus subtilis and Bacillus licheniformis had the most significant positive impact on their productive performance, it allowed to increase egg production by 7,81 %, egg laying intensity by 5,0 %, egg mass yield by 9,77 %, while reducing feed expenditures for 10 eggs by 13,35 %. The yield of hatching eggs has been increased by 7,03 %, hatchability of chickens from laid and fertilized eggs by 8,33 and 8,35 %, brooding waste decreased by 21,74 %. Hematological parameters of quails during the whole experiment were within the physiological norm. The economic effect calculated on the basis of data on the cost of compound feed, probiotics and the cost of sold eggs of quail laying was 14,56 % in the 3rd experimental group (in relation to the control group).


2019 ◽  
Vol 19 (8) ◽  
pp. 567-578 ◽  
Author(s):  
Marcus Vinicius Nora de Souza ◽  
Thais Cristina Mendonça Nogueira

Nowadays, tuberculosis (TB) is an important global public health problem, being responsible for millions of TB-related deaths worldwide. Due to the increased number of cases and resistance of Mycobacterium tuberculosis to all drugs used for the treatment of this disease, we desperately need new drugs and strategies that could reduce treatment time with fewer side effects, reduced cost and highly active drugs against resistant strains and latent disease. Considering that, 4H-1,3-benzothiazin-4-one is a promising class of antimycobacterial agents in special against TB-resistant strains being the aim of this review the discussion of different aspects of this chemical class such as synthesis, mechanism of action, medicinal chemistry and combination with other drugs.


2020 ◽  
Vol 94 (12) ◽  
pp. 2421-2427
Author(s):  
R. Kh. Saryeva ◽  
N. S. Kozhevnikova ◽  
L. N. Maskaeva ◽  
V. F. Markov ◽  
V. I. Voronin ◽  
...  

1992 ◽  
Vol 267 (31) ◽  
pp. 22108-22114
Author(s):  
I.C. Kim ◽  
J.H. Cha ◽  
J.R. Kim ◽  
S.Y. Jang ◽  
B.C. Seo ◽  
...  

Author(s):  
Wenxue Fan ◽  
Hai Hao

Abstract Grain refinement has a significant influence on the improvement of mechanical properties of magnesium alloys. In this study, a series of Al–Ti–C-xGd (x = 0, 1, 2, 3) master alloys as grain refiners were prepared by self-propagating high-temperature synthesis. The synthesis mechanism of the Al–Ti–C-xGd master alloy was analyzed. The effects of Al–Ti–C-xGd master alloys on the grain refinement and mechanical properties of AZ31 (Mg-3Al-1Zn-0.4Mn) magnesium alloys were investigated. The results show that the microstructure of the Al–Ti–C-xGd alloy contains α-Al, TiAl3, TiC and the core–shell structure TiAl3/Ti2Al20Gd. The refining effect of the prepared Al–Ti–C–Gd master alloy is obviously better than that of Al–Ti–C master alloy. The grain size of AZ31 magnesium alloy was reduced from 323 μm to 72 μm when adding 1 wt.% Al–Ti–C-2Gd master alloy. In the same condition, the ultimate tensile strength and elongation of as-cast alloy were increased from 130 MPa, 7.9% to 207 MPa, 16.6% respectively.


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