scholarly journals Biosurfactant production by a Bacillus megaterium strain

2020 ◽  
Vol 15 (1) ◽  
pp. 629-637
Author(s):  
Mihaela Marilena Stancu
Keyword(s):  
Yeast Extract ◽  
Bacillus Megaterium ◽  
Biofilm Formation ◽  
Petroleum Hydrocarbon ◽  
Biosurfactant Production ◽  
Positive Bacterium ◽  
Promising Candidate ◽  
Ph Values ◽  
Proteose Peptone ◽  
Long Chain

AbstractThe aim of the present study was to investigate the ability of Bacillus megaterium IBBPo17 (GenBank KX499518) cells to produce biosurfactant when the growth was done in the presence of long-chain n-alkane n-hexadecane on medium supplemented with yeast extract, proteose peptone, starch, or cellulose. B. megaterium IBBPo17 revealed a higher growth in the presence of n-hexadecane when the medium was supplemented with yeast extract, proteose peptone, or starch, compared with cellulose. Biosurfactant production was higher when B. megaterium IBBPo17 was grown in the presence of n-hexadecane on yeast extract, proteose peptone, or starch supplemented medium, compared with biosurfactant produced on cellulose supplemented medium. A direct correlation between cell growth and biosurfactant production was observed. When the growth of B. megaterium IBBPo17 cells was higher, the decrease in pH values of the medium was higher too, and more amount of CO2 was released. Changes in cell morphology, aggregation of the cells in clusters, and biofilm formation were observed when B. megaterium IBBPo17 was grown in the presence of n-hexadecane on medium supplemented with yeast extract, proteose peptone, starch, or cellulose. Due to its physiological abilities, this Gram-positive bacterium could be a promising candidate for the bioremediation of petroleum hydrocarbon polluted environments.

scholarly journals Construction of an inducible amyloid expression circuit in Bacillus megaterium: A case study with CsgA and TasA

2019 ◽  
Author(s):  
Elin M. Larsson ◽  
John B. McManus ◽  
Richard M. Murray
Keyword(s):  
Synthetic Biology ◽  
Cell Survival ◽  
Bacillus Megaterium ◽  
Biofilm Formation ◽  
Water Remediation ◽  
Hostile Environment ◽  
Promising Candidate ◽  
Functional Amyloids ◽  
Future Work

AbstractEnvironmental applications of synthetic biology such as water remediation require engineered strains to function robustly in a fluctuating and potentially hostile environment. The construction of synthetic biofilm formation circuits could potentially alleviate this issue by promoting cell survival. Towards this end, we construct a xylose-inducible system for the expression of the functional amyloids CsgA and TasA in the soil bacterium Bacillus megaterium. We find that although both amyloids are expressed, only TasA is successfully exported from the cells. Furthermore, expression of CsgA results in a significant growth penalty for the cells while expression of TasA does not. Finally, we show that TasA expression conveys a small but detectable increase in cells’ adhesion to nickel beads. These results suggest that TasA is a promising candidate for future work on synthetic biofilm formation in B. megaterium.

scholarly journals UJI PRODUKSI BIOSURFAKTAN OLEH Pseudomonas sp. PADA SUBSTRAT YANG BERBEDA

2007 ◽  
Vol 12 (2) ◽  
pp. 181-185 ◽  
Author(s):  
Fatimah Fatimah
Keyword(s):  
Surface Tension ◽  
Stationary Phase ◽  
Yeast Extract ◽  
Petroleum Hydrocarbon ◽  
Biosurfactant Production ◽  
Lubricating Oil ◽  
Pseudomonas Sp ◽  
Emulsification Activity ◽  
Microbial Metabolite ◽  
Surface Tension Reduction

Biosurfactant, microbial metabolite whose properties like surfactant, was suggested to replace chemically synthesized surfactant for take in hand environtmental pollution by petroleum hydrocarbon. This work was done to examine potency of Pseudomonas sp. isolated from Tanjung Perak Harbor to produce biosurfactant. Also, to know the effect of different substrates (glucose plus yeast extract, lubricating oil and hexadecane) toward biosurfactant production. Pseudomonas sp. grown in mineral synthetic water and biosurfactant production was measured on stationary phase. Biosurfactant production based on emulsification activity and surface tension reduction of supernatant (using Du Nouy tensiometer). Solar, lubricating oil, and hexadecane were used to examine emulsification activity. Results indicated that Pseudomonas sp. have a potency to produce biosurfactant. Surface tension of supernatant decreased up to 20 dyne/cm, when grown on hexadecane substrate. Hexadecane is the best growing substrate for biosurfactant production than others.

OBSERVATIONS ON AMYLOLYTIC BACTERIA: III. CULTURAL CONDITIONS INFLUENCING THE BREAKDOWN OF STARCH BY STENOTHERMOPHILIC BACTERIA BELONGING TO BACILLUS STEAROTHERMOPHILUS

1952 ◽  
Vol 30 (4) ◽  
pp. 360-370 ◽  
Author(s):  
Egon Stark ◽  
P. A. Tetrault
Keyword(s):  
Yeast Extract ◽  
Bacillus Stearothermophilus ◽  
Soluble Starch ◽  
The Other ◽  
Ph Changes ◽  
Proteose Peptone ◽  
Cultural Conditions ◽  
Initial Ph ◽  
Commercial Medium ◽  
Agar Media

Thirty-five cultures of Bacillus stearothermophilus hydrolyzed five starches under various cultural conditions. Hydrolysis occurred regardless of the type, brand, or batch of starch; regardless of the initial pH or of the subsequent pH changes of the medium. Starch in broth was better attacked than in agar media. Some cultures hydrolyzed 0.5%, but not 1% starch; others hydrolyzed easily 10% soluble starch. Length of incubation was important. Certain cultures never formed acid or sugar from starch. Dextrinization was a more reliable indication of starch hydrolysis than was the formation of acid or sugar. Soluble starch gave more consistent results in repeated experiments than did nonsoluble starches. The type of protein medium determines strongly the formation of amylase. Trypticase was the best commercial medium, yeast extract came second. The other 10 media yielded fewer amylolytic cultures. Yeast extract added to media enhanced amylase formation, except with trypticase. Tryptose, proteose-peptone, and neopeptone inhibited the growth of most cultures.

scholarly journals Factorial Design to Optimize Biosurfactant Production byYarrowia lipolytica

2010 ◽  
Vol 2010 ◽  
pp. 1-8 ◽  
Author(s):  
Gizele Cardoso Fontes ◽  
Priscilla Filomena Fonseca Amaral ◽  
Marcio Nele ◽  
Maria Alice Zarur Coelho
Keyword(s):  
Surface Tension ◽  
Factorial Design ◽  
Ammonium Sulfate ◽  
Yeast Extract ◽  
Carbon Sources ◽  
Nitrogen Sources ◽  
Biosurfactant Production ◽  
Standard Process ◽  
Emulsification Index ◽  
Full Factorial

In order to improve biosurfactant production byYarrowia lipolyticaIMUFRJ 50682, a factorial design was carried out. A24full factorial design was used to investigate the effects of nitrogen sources (urea, ammonium sulfate, yeast extract, and peptone) on maximum variation of surface tension (ΔST) and emulsification index (EI). The best results (67.7% of EI and 20.9 mNm−1ofΔST) were obtained in a medium composed of 10 g 1−1of ammonium sulfate and 0.5 g 1−1of yeast extract. Then, the effects of carbon sources (glycerol, hexadecane, olive oil, and glucose) were evaluated. The most favorable medium for biosurfactant production was composed of both glucose (4% w/v) and glycerol (2% w/v), which provided an EI of 81.3% and aΔST of 19.5 mN m−1. The experimental design optimization enhancedΔEI by 110.7% andΔST by 108.1% in relation to the standard process.

scholarly journals Self-assembly of alkyl chains of fatty acids in papermaking systems: A review of related pitch issues, hydrophobic sizing, and pH effects

BioResources ◽  
2020 ◽  
Vol 15 (2) ◽  
pp. 4591-4635
Author(s):  
Martin A. Hubbe ◽  
Douglas S. McLean ◽  
Karen R. Stack ◽  
Xiaomin Lu ◽  
Anders Strand ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Self Assembly ◽  
Review Article ◽  
Ph Effects ◽  
Monolayer Films ◽  
Alkyl Chains ◽  
Ph Values ◽  
Self Association ◽  
Long Chain

This review article considers the role of fatty acids and the mutual association of their long-chain (e.g. C18) alkyl and alkenyl groups in some important aspects of papermaking. In particular, published findings suggest that interactions involving fatty acids present as condensed monolayer films can play a controlling role in pitch deposition problems. Self-association among the tails of fatty acids and their soaps also helps to explain some puzzling aspects of hydrophobic sizing of paper. When fatty acids and their soaps are present as monolayers in papermaking systems, the pH values associated with their dissociation, i.e. their pKa values, tend to be strongly shifted. Mutual association also appears to favor non-equilibrium multilayer structures that are tacky and insoluble, possibly serving as a nucleus for deposition of wood extractives, such, as resins and triglyceride fats, in pulp and paper systems.

scholarly journals DETERMINATION OF OPTIMUM CULTURE CONDITIONS FOR MYCELIAL GROWTH OF Macrolepiota procera MUSHROOM

2020 ◽  
Vol 19 (1) ◽  
pp. 11-20
Author(s):  
Aysun Pekşen ◽  
Beyhan Kibar
Keyword(s):  
Yeast Extract ◽  
Mycelial Growth ◽  
Nitrogen Sources ◽  
Culture Conditions ◽  
Malt Extract ◽  
The Public ◽  
Carbon And Nitrogen ◽  
Ph Values ◽  
Incubation Temperatures ◽  
Macrolepiota Procera

Macrolepiota procera, commonly called the Parasol Mushroom, is a delicious mushroom collected from the nature and commonly consumed by the public in many regions of Turkey. This study was conducted to determine the optimum culture conditions (pH, temperature, carbon and nitrogen sources) for mycelial growth of M. procera. Three pH values (pH 5.0, 5.5 and 6.0), four incubation temperatures (15, 20, 25 and 30°C), seven carbon (C) sources (dextrose, glucose, lactose, maltose, mannitol, sucrose and xylose) and six nitrogen (N) sources ((NH4)2HPO4, NH4NO3 and Ca(NO3)2, malt extract, peptone and yeast extract) were investigated. In the second step of the study, the effect of seven pH values (4.0, 4.5, 5.0, 5.5, 6.0, 6.5 and 7.0) on the mycelial colony diameter was examined at 20 and 25°C since these temperatures gave the best mycelial growth in the previously conducted temperature experiment. The best mycelial growth was determined at pH 6.0. The optimum temperature for mycelial growth of M. procera was found as 25°C. The use of glucose as carbon source and yeast extract and peptone as nitrogen source in the culture medium gave the best results for mycelial growth. Determining of optimum culture conditions for mycelial growth of M. procera will provide important contributions to the fortcoming studies on it’s commercially cultivation in Turkey.

Enumeration of starter cultures in fermented milks

1996 ◽  
Vol 63 (1) ◽  
pp. 151-158 ◽  
Author(s):  
Hamid B. Ghoddusi ◽  
Richard K. Robinson
Keyword(s):  
Quality Control ◽  
Prussian Blue ◽  
Yeast Extract ◽  
Streptococcus Thermophilus ◽  
Starter Cultures ◽  
Lactobacillus Delbrueckii ◽  
Proteose Peptone ◽  
Different Strains ◽  
Differential Counts

SummarySome media available for the isolation and enumeration of starter cultures employed for the manufacture of cheese, yogurt and bio-yogurt were examined. Reddy's medium or a modification of Elliker's medium was found to be most satisfactory forLactococcusspp., while trypticase phytone yeast (TPY) agar with a mixture of antibiotics proved suitable for the discrete enumeration ofBifidobacteriumspp. The inclusion of Prussian blue (PB) in reinforced clostridial medium or tryptone proteose peptone yeast extract (TPPY) agar gave excellent differential counts for the starter bacteria in yogurt even when the culture was imbalanced, while TPPY (PB) agar allowed the visible separation of all four of the organisms that might be found in a typical bio-yogurt, namelyLactobacillus delbrueckiisubsp.bulgaricus, Streptococcus thermophilus, a,Bifidobacteriumsp. andLb. acidophilus. It was noted that variation among different strains of any given species could change the expected reactions, so for quality control purposes the suggested media may need to be modified to cope with the specific cultures in use.

scholarly journals Synthesis, In Silico, and In Vitro Evaluation of Long Chain Alkyl Amides from 2-Amino-4-Quinolone Derivatives as Biofilm Inhibitors

Molecules ◽  
2019 ◽  
Vol 24 (2) ◽  
pp. 327 ◽  
Author(s):  
Mariana Espinosa-Valdés ◽  
Sara Borbolla-Alvarez ◽  
Ana Delgado-Espinosa ◽  
Juan Sánchez-Tejeda ◽  
Anabelle Cerón-Nava ◽  
...  
Keyword(s):  
Quorum Sensing ◽  
Biofilm Formation ◽  
Active Sites ◽  
Multidrug Resistant ◽  
Health Concern ◽  
Resistant Bacteria ◽  
Biofilm Inhibition ◽  
Amide Derivatives ◽  
Long Chain

Infection from multidrug resistant bacteria has become a growing health concern worldwide, increasing the need for developing new antibacterial agents. Among the strategies that have been studied, biofilm inhibitors have acquired relevance as a potential source of drugs that could act as a complement for current and new antibacterial therapies. Based on the structure of 2-alkyl-3-hydroxy-4-quinolone and N-acylhomoserine lactone, molecules that act as mediators of quorum sensing and biofilm formation in Pseudomonas aeruginosa, we designed, prepared, and evaluated the biofilm inhibition properties of long chain amide derivatives of 2-amino-4-quinolone in Staphylococcus aureus and P. aeruginosa. All compounds had higher biofilm inhibition activity in P. aeruginosa than in S. aureus. Particularly, compounds with an alkyl chain of 12 carbons exhibited the highest inhibition of biofilm formation. Docking scores and molecular dynamics simulations of the complexes of the tested compounds within the active sites of proteins related to quorum sensing had good correlation with the experimental results, suggesting the diminution of biofilm formation induced by these compounds could be related to the inhibition of these proteins.

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