EFFECT OF DIFFERENT NITROGEN SOURCES, INOCULUM SIZE AND FERMENTATION VESSEL SIZE ON ANTIMICROBIAL ACTIVITY OF ASPERGILLUS IBERICUS

Species of the Celastraceae family are traditionally consumed in different world regions for their stimulating properties. Celastrol, a triterpene methylene quinone isolated from plants of celastraceas, specifically activates satiety centers in the brain that play an important role in controlling body weight. In this work, the antimicrobial activity and mechanism of action of celastrol and a natural derivative, pristimerin, were investigated in Bacillus subtilis. Celastrol showed a higher antimicrobial activity compared with pristimerin, being active against Gram-positive bacteria with minimum inhibitory concentrations (MICs) that ranged between 0.16 and 2.5 µg/mL. Killing curves displayed a bactericidal effect that was dependent on the inoculum size. Monitoring of macromolecular synthesis in bacterial populations treated with these compounds revealed inhibition in the incorporation of all radiolabeled precursors, but not simultaneously. Celastrol at 3 µg/mL and pristimerin at 10 µg/mL affected DNA and RNA synthesis first, followed by protein synthesis, although the inhibitory action on the uptake of radiolabeled precursors was more dramatic with celastrol. This compound also caused cytoplasmic membrane disruption observed by potassium leakage and formation of mesosome-like structures. The inhibition of oxygen consumption of whole and disrupted cells after treatments with both quinones indicates damage in the cellular structure, suggesting the cytoplasmic membrane as a potential target. These findings indicate that celastrol could be considered as an interesting alternative to control outbreaks caused by spore-forming bacteria.

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Pectinase production by Aspergillus niger isolated from decomposed apple skin

Bangladesh Journal of Scientific and Industrial Research ◽

10.3329/bjsir.v48i1.15410 ◽

2013 ◽

Vol 48 (1) ◽

pp. 25-32 ◽

Cited By ~ 3

Author(s):

S Islam ◽

B Feroza ◽

AKMR Alam ◽

S Begum

Keyword(s):

Aspergillus Niger ◽

Incubation Temperature ◽

Nitrogen Sources ◽

Inoculum Size ◽

Point Of View ◽

Media Composition ◽

Maximal Level ◽

Pectinolytic Activity ◽

Pectinase Activity ◽

Pectinase Production

Pectinase activity among twelve different fungal strains, Aspergillus niger IM09 was identified as a potential one to produce maximal level 831 U/g at pH 4.0. Media composition, incubation temperature, incubation time, substrate concentration, aeration, inoculum size, assay temperature and nitrogen sources were found to effect pectinase activity. Moisture content did not affect the activity significantly. Media composition was varied to optimize the enzyme production in solid state fermentation. It was observed that the highest pectinase activity of 831.0 U/g was found to produce in presence of yeast extract as a nitrogen source in combination with ammonium sulfate in assay media. Aeration showed positive significant effects on pectinase production 755 U/g at 1000 ml flasks. The highest pectinase production was found at 2 g pectin (521 U/g) used as a substrate. Pectinolytic activity was found to have undergone catabolite repression with higher pectin concentration (205 U/g at 5 g pectin). The incubation period to achieve maximum pectinase activity by the isolated strain Aspergillus niger IM09 was 3 days, which is suitable from the commercial point of view. DOI: http://dx.doi.org/10.3329/bjsir.v48i1.15410 Bangladesh J. Sci. Ind. Res. 48(1), 25-32, 2013

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Growth morphology of Streptomyces akiyoshiensis in submerged culture: influence of pH, inoculum, and nutrients

Canadian Journal of Microbiology ◽

10.1139/m92-016 ◽

1992 ◽

Vol 38 (2) ◽

pp. 98-103 ◽

Cited By ~ 20

Author(s):

M. A. Glazebrook ◽

L. C. Vining ◽

R. L. White

Keyword(s):

Nitrogen Sources ◽

Growth Conditions ◽

Culture Conditions ◽

Inoculum Size ◽

Clear Correlation ◽

Growth Morphology ◽

Physiological Control ◽

Submerged Cultures ◽

Pellet Formation ◽

Culture Influence

Most media in which the growth of shaken submerged cultures of Streptomyces akiyoshiensis was examined did not support the formation of well-dispersed mycelial suspensions. Investigation of the culture conditions promoting dispersed growth showed the pH of the culture medium to be of critical importance; an initial value of 5.5 minimized aggregation of the mycelium while supporting adequate biomass production. In cultures started at this pH, spore inocula gave better mycelial dispersal than did vegetative inocula; with spore inocula, growth morphology was also less affected by inoculum size. The composition of the nutrient solution influenced the extent of mycelial dispersal; slow growth was often associated with clumping but no clear correlation was observed between pellet formation and the ability of carbon or nitrogen sources to support rapid growth. Increasing the phosphate concentration from 0.5 to 15 mM caused a modest decrease in mycelial aggregation. Conditions promoting a well-dispersed mycelium suitable for studying the physiological control of secondary metabolism also supported the formation of 5-hydroxy-4-oxonorvaline by S. akiyoshiensis. Key words: Streptomyces akiyoshiensis, mycelial aggregation, growth conditions.

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Berberine sulfate: antimicrobial activity, bioassay, and mode of action

Canadian Journal of Microbiology ◽

10.1139/m69-190 ◽

1969 ◽

Vol 15 (9) ◽

pp. 1067-1076 ◽

Cited By ~ 195

Author(s):

A. H. Amin ◽

T. V. Subbaiah ◽

K. M. Abbasi

Keyword(s):

Staphylococcus Aureus ◽

Antimicrobial Activity ◽

Antibacterial Activity ◽

Deoxyribonucleic Acid ◽

Test Organism ◽

Inoculum Size ◽

Gram Negative Bacteria ◽

Gram Negative ◽

Rna And Protein Synthesis ◽

And Staphylococcus Aureus

Berberine sulfate was shown to possess antimicrobial activity against a wide variety of microorganisms including Gram-positive and Gram-negative bacteria, fungi, and protozoa. The antibacterial activity against Vibrio cholerae and Staphylococcus aureus was dependent on the inoculum size of the test organism and pH of the medium. A method of microbiological assay sensitive to 5–10 μg/ml of the drug was developed. The drug was shown to exert a more rapid antibacterial activity than chloramphenicol and tetracycline on V. cholerae, the K values being 2.4 ×10−2 sec−1, 7.8 × 10−3 sec−1, and 5.2 × 10−3 sec−1 respectively. Berberine sulfate was shown to be bacteriocidal to V. cholerae and bacteriostatic to S. aureus, at concentrations of 35 and 50 μg/ml. In both these organisms concentrations of 35 and 50 μg/ml of the drug inhibited ribonucleic acid (RNA) and protein synthesis almost immediately after the addition of the drug. There was little effect on deoxyribonucleic acid (DNA) synthesis at these concentrations.

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Chitinase Production from Locally Isolated Bacillus cereus GS02 from Chitinous Waste Enriched Soil

Journal of Advances in Biology & Biotechnology ◽

10.9734/jabb/2020/v23i130137 ◽

2020 ◽

pp. 39-48

Author(s):

Garima Dukariya ◽

Anil Kumar

Keyword(s):

Bacillus Cereus ◽

Fungal Pathogens ◽

Higher Plants ◽

Nitrogen Sources ◽

Inoculum Size ◽

Secondary Screening ◽

Structural Carbohydrate ◽

Biochemical Identification ◽

Chitinase Production ◽

Commercial Applications

Background and Objective: Chitin is world’s second most abundant structural carbohydrate in nature and is found as a structural component in the cell wall of fungi and exoskeletons of invertebrates. During senescence, it is degraded by the enzyme, chitinase. In addition, chitinase has been exploited for various commercial applications such as control of insects and fungal pathogens in order to protect the crops, waste management, cosmetics and food industries. Chitinases have been found to be widely distributed in various organisms including viruses, animals, bacteria, fungi, higher plants and insects. In the present study, various soil samples enriched in chitinous waste were screened for the isolation of bacteria capable of producing chitinase. Methodology: Chitinase producing bacteria were isolated using serial dilution plating technique onto different agar media. Primary and secondary screening were performed and the isolate producing maximum chitinase was selected for biochemical identification and 16s rRNA sequencing. The secretion of extracellular chitinase by this strain was optimized with respect to pH, temperature, incubation time, substrate concentration, carbon and nitrogen sources and inoculum size. All these components were optimized using OFAT (one factor at a time) approach. Results: A total of 29 bacterial isolates were found exhibiting secretion of extracellular chitinase as determined using zones of clearance. Based on the area of zone of clearance, six isolates were selected for secondary screening and the most potent isolate was identified as Bacillus cereus. The maximum chitinase production by this strain was obtained at 37°C and pH 7.0 after 48 hours of incubation. The maximum chitinase secretion was observed on addition of 1% colloidal chitin and 0.05% yeast extract in the medium.

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Production of cellulase by Mucor ramanniacus using submerged fermentation and its applications in biodegradation of agro-industrial waste

10.21203/rs.3.rs-342058/v1 ◽

2021 ◽

Author(s):

Taiwo Dorcas Ibukunoluwa ◽

Ademakinwa Adedeji Nelson ◽

Zainab Adenike Ayinla ◽

Femi Kayode Agboola

Keyword(s):

Specific Activity ◽

Protein A ◽

Nitrogen Sources ◽

Tween 80 ◽

Growth Conditions ◽

Cellulase Production ◽

Industrial Applications ◽

Inoculum Size ◽

Industrial Wastes ◽

Triton X

Abstract This study was undertaken to isolate and identify a novel cellulase-producing strain from a waste site (7°28’11’’N 4°31’24’’E), optimise the growth conditions, partially purify and biochemically characterise the enzyme. The potentials of the purified cellulase to hydrolyse the lignocellulosic component of some agro-industrial wastes (e.g. orange peels etc.) was also investigated. The best cellulase-producing fungus was identified as Mucor ramanniacus and the optimum conditions for cellulase production were pH (4.5), inoculum size (12 mm), carbon and nitrogen sources were carboxymethyl cellulose and sodium nitrate respectively resulting in a specific activity of 1423 Units/mg protein. A purification fold of 1.56 and 45.37 % yield were obtained after purification. The optimum pH and temperature were at 9.0 and 40°C respectively. The kinetic parameters were 0.63 ± 0.495 mg/ml, 20.21 ± 11.28 U/ml, 1001.4s− 1 for Km and Vmax and kcat respectively. Na+, K+, Ca+, Cysteine, β-mercaptoethanol and SDS were activators while Tween 80, Triton X-100 EDTA, Hg2+ and Ba2+ inhibited the enzyme. M. ramanniacus cellulase hydrolysed all agro-industrial wastes used. The partially purified M. ramanniacus cellulase showed great potential in biodegradation of various lignocellulosic substrates and the biochemical characteristics exhibited makes it suitable in industrial applications.

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Antagonism of Helicobacter pylori by Bacteriocins of Lactic Acid Bacteria

Journal of Food Protection ◽

10.4315/0362-028x-66.1.3 ◽

2003 ◽

Vol 66 (1) ◽

pp. 3-12 ◽

Cited By ~ 63

Author(s):

TAE-SEOK KIM ◽

JI-WOON HUR ◽

MYEONG-AE YU ◽

CHAN-ICK CHEIGH ◽

KYUNG-NAM KIM ◽

...

Keyword(s):

Antimicrobial Activity ◽

Helicobacter Pylori ◽

Lactic Acid ◽

Lactic Acid Bacteria ◽

Inoculum Size ◽

Strain Atcc ◽

Initial Inoculum ◽

H Pylori ◽

Strain Dependent

Antimicrobial activity of seven bacteriocins produced by lactic acid bacteria against Helicobacter pylori strains (ATCC 43504, Deutsche Sammlung von Mikroorganismen und Zellkulturen GmbH [DSM] 4867, DSM 9691, and DSM 10242) was investigated in vitro using a broth microdilution assay. The bacteriocins chosen for the study were nisin A; lacticins A164, BH5, JW3, and NK24; pediocin PO2; and leucocin K. Antimicrobial activity of the bacteriocins varied among the H. pylori strains tested, of which strain ATCC 43504 was the most tolerant. Among the bacteriocins tested, lacticins A164 and BH5 produced by Lactococcus lactis subsp. lactis A164 and L. lactis BH5, respectively, showed the strongest antibacterial activity against H. pylori strains. MICs of the lacticins against H. pylori strains, when assessed by the critical dilution micromethod, ranged from 0.097 to 0.390 mg/liter (DSM strains) or from 12.5 to 25 mg/liter (ATCC 43504), supporting the strain-dependent sensitivity of the pathogen. Pediocin PO2 was less active than the lacticins against four strains of H. pylori, and leucocin K was the least active peptide, with no inhibition toward H. pylori ATCC 43504. Anti-Helicobacter activity of lacticin A164 was dependent on initial inoculum size as well as concentration of the bacteriocin added.

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Validation of Fermentative Parameters for Efficient Succinate Production in Batch Operation by Actinobacillus succinogenes 130ZT

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.550-553.1448 ◽

2012 ◽

Vol 550-553 ◽

pp. 1448-1454

Author(s):

Apichai Sawisit ◽

Supaluk Seesan ◽

Sitha Chan ◽

Sunthorn Kanchanatawee ◽

Sirima Suvarnakuta Jantama ◽

...

Keyword(s):

Yeast Extract ◽

Nitrogen Sources ◽

Inoculum Size ◽

Actinobacillus Succinogenes ◽

Brewer’S Yeast ◽

Succinate Production ◽

Brewer's Yeast ◽

Lactose Fermentation ◽

Initial Ph ◽

The Cost

Succinate is an important platform molecule in the synthesis of a number of commodity and specialty chemicals. In the present study, the effects of different carbon and nitrogen sources, initial pH of the growth medium (pH 4.5-9.0), and temperature (25-45°C) on the fermentative succinate production by Actinobacillus succinogenes 130ZT were investigated in 100 mL anaerobic bottles. The results revealed that the highest concentration of succinate at 6.28 g/L was produced from 10 g/L of glucose or lactose in the medium containing 5 g/L yeast extract at 24 h. However, a comparable concentration of succinate was also produced when the medium was supplemented with 5 g/L spent brewer’s yeast extract. Based on these results, the cost effectiveness of succinate production could be improved by the use of glucose or lactose fermentation supplemented with spent brewer’s yeast extract. Optimized initial pH at 8.0, temperature at 37 °C, and inoculum size at 6% (v/v) provided the best succinate production at the concentration of 6.37 g/L with a yield of 68.73%.

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Prospecting the antimicrobial and antibiofilm potential of Chaetomium globosum an endophytic fungus from Moringa oleifera

AMB Express ◽

10.1186/s13568-020-01143-y ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Navdeep Kaur ◽

Daljit Singh Arora

Keyword(s):

Antimicrobial Activity ◽

Endophytic Fungus ◽

Moringa Oleifera ◽

Wide Spectrum ◽

Fold Increase ◽

Viable Cell ◽

Inoculum Size ◽

Chaetomium Globosum ◽

Antimicrobial Potential ◽

Antibiotic Effect

Abstract The current study prospects the antimicrobial potential of an endophytic fungus Chaetomium globosum which showed a wide spectrum antimicrobial activity against the tested pathogenic microorganisms. This is apparently the first report where Chaetomium globosum as an endophyte from Moringa oleifera showed antimicrobial potential and is optimized for physiochemical parameters to enhance the antimicrobial metabolites production. In the classical optimization yeast peptone dextrose medium, inoculum size of two discs, incubation period of 6 days, production temperature of 25 ºC and pH 7 was best supportive for optimal growth and antimicrobial activity whereas maltose and ammonium nitrate were the best carbon and nitrogen sources, respectively. The statistical optimization resulted in up to 1.33 fold increase in antimicrobial activity. Chloroform was found to be the best extractant. The chloroformic extract showed minimum inhibitory concentration ranging from 0.05 to 5 mg/ml and its microbicidal nature was established by viable cell count studies. The efficacy of the extract was also established in terms of post antibiotic effect which ranged from 2 to 20 h. The chloroformic extract exhibited the good antibiofilm potential and was also found to be biosafe. The clinical relevance of the study was justified as it showed good antimicrobial efficacy against some resistant clinical isolates, too.

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Cost-Effective Production and Optimization of Alkaline Xylanase by Indigenous Bacillus mojavensis AG137 Fermented on Agricultural Waste

Enzyme Research ◽

10.4061/2011/593624 ◽

2011 ◽

Vol 2011 ◽

pp. 1-9 ◽

Cited By ~ 18

Author(s):

Abbas Akhavan Sepahy ◽

Shokoofeh Ghazi ◽

Maryam Akhavan Sepahy

Keyword(s):

Agricultural Waste ◽

Xylanase Activity ◽

Nitrogen Sources ◽

Cost Effective ◽

Inoculum Size ◽

Alkaline Condition ◽

Xylanase Production ◽

Bacillus Mojavensis ◽

Oat Bran ◽

Higher Temperature

A xylanase producer Bacillus mojavensis strain, called AG137, isolated from cotton farm (Kashan-Iran). The optimal xylanase activity reached at 55∘C & pH 9.0. Enzyme yield was studied using a medium with different agricultural wastes as inducers. Xylanase production of about 249.308 IU/mL was achieved at pH 8 and 37∘C, within 48 h submerged fermentation in enzyme production medium supplemented with 2% (w/v) oat bran as an optimum carbon source. A mixture of 1% (w/v) yeast extract and 1% (w/v) tryptone as optimum nitrogen sources, agitation speed 200 rpm, and inoculum size 2% (v/v) were the optimums for maximum production. Accordingly, xylanase yield from 194.68 IU/mL under non-optimized fermentation condition enhanced to 302.466 IU/mL in optimized condition. Screened xylanase is thermostable, presenting 70% stability at 60∘C during 30 min. Further enzyme incubation in higher temperature caused a decrease in the residual enzyme activity, yet it retained 68%–50% of its activity after 1 hour from 45∘C to 55∘C. Besides, it is stable in pH 9 and 10, maintaining over 70% of its activity for 2 h. The enzyme also could preserve 71% and 63% of its initial activity after 3 hours of pre-incubation in the same alkaline condition. Produced xylanase therefore was introduced as an alkaline-active and stable one, displaying suitable thermostability feature, confirmed by HPLC analysis. Hence, all xylanase properties highlight its promising uses in industrial scale.

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