Antifungal properties exhibited by bacteria isolated from agriculturally cultivable soils and their antagonistic nature towards fungal phytopathogen suppression

2016 ◽  
Vol 35 (1) ◽  
Author(s):  
Ch. Usha Rani ◽  
Priyanka ◽  
A. Srinivasa Rao
Keyword(s):  
Bacillus Cereus ◽  
Biochemical Characterization ◽  
Rhizosphere Soil ◽  
Agar Medium ◽  
Chitinolytic Activity ◽  
Culture Methods ◽  
Bacterial Cultures ◽  
Nutrient Agar Medium ◽  
Fungal Antagonism ◽  
Fungal Phytopathogen

Soil samples collected from rhizosphere soil, cultivable field soil, Rhizoplane soil of paddy plants and were used to isolate bacteria by culture methods of which thirty two bacterial cultures were identified with diverse colony characteristics on nutrient agar medium and biochemical characterization. Sixteen bacterial isolates were selected for screening fungal antagonism on PDA and were further tested against <italic>Fusarium</italic> and <italic>Rhizoctonia species.</italic> In this study, two <italic>Pseudomonas strains</italic> (RB15, RB30) and <italic>Bacillus cereus</italic> (RB13) were cyanogen producers. Both strains of <italic>Pseudomonas</italic> RB15 and RB30 and <italic>Bacillus cereus</italic> (RB13) were also siderophore producers. Only three isolates showed chitinolytic activity; <italic>Serratia marcesens (RB24), Bacillus cereus (RB13) and Enterobacter cancerogenus</italic> (RB17).

scholarly journals Screening, Isolation and Biochemical Characterization of Laccase Producing Bacteria from Contaminated Sites

2021 ◽  
Vol 71 (2) ◽  
Author(s):  
Siva Jyothi J. ◽  
Kishore Kumar K. ◽  
Hema Latha E.
Keyword(s):  
Biochemical Characterization ◽  
Agar Medium ◽  
Nutrient Agar ◽  
Laccase Production ◽  
Bacterial Strains ◽  
Isolation And Identification ◽  
Leading Role ◽  
Degrading Bacteria ◽  
Nutrient Agar Medium ◽  
Guntur District

Screening and isolation of Laccase producing bacteria from Guntur District soil was carried out to assess the diversity of Lignocellulose degrading bacteria. Isolation and identification of environmental friendly bacteria for lignin degradation becomes an essential one, because all the researchers are mainly concentrating on fungal strains. However, bacteria seem to play a leading role in decomposing lignin. For isolation of Laccase producing bacteria nutrient agar medium containing guaiacol was used. Total nine bacterial strains were isolated from soil samples collected from different regions of Guntur district. Preliminary screening of bacterial strains was carried out on guaiacol containing nutrient agar medium for laccase production. Formation of green colour using ABTS (2,2'- azinobis(3-ethylbenzthiazoline-6-sulfonate) confirms the capability of laccase production by the bacterial strains. Nine bacterial strains showed positive results. High laccase producing bacterial isolates were examined for morphological and biochemical characteristics according to Bergey’s Manual of Systematic Bacteriology. The predominant isolates were identified as Bacillus and Enterobacter species.

Biochemical characterization of a cortexless mutant of a variant of Bacillus cereus

1976 ◽  
Vol 22 (7) ◽  
pp. 1007-1012 ◽  
Author(s):  
Susanne M. Pearce
Keyword(s):  
Cell Wall ◽  
Fatty Acid Composition ◽  
Fatty Acid ◽  
Bacillus Cereus ◽  
Biochemical Characterization ◽  
Diaminopimelic Acid ◽  
Peptidoglycan Synthesis ◽  
Biochemical Lesion ◽  
Do So

Previous studies on this cortexless mutant of Bacillus cereus var. alesti indicated that the forespore membrane was the site of the biochemical lesion. This hypothesis is supported by the results presented here: fatty acid composition of sporulating cells of the mutant is altered, while in vegetative cells it is comparable to the parent; soluble precursors of peptidoglycan synthesis are accumulated in the mutant, at the time of cortex formation; homogenates of the mutant prepared at the time of cortex formation are unable to incorporate tritiated diaminopimelic acid into peptidoglycan, while homogenates of cells forming germ cell wall do so to an extent comparable to that of the parent; lipid-linked intermediates are formed by the mutant as in the parent. Apparently the mutant is unable either to transfer disaccharide penta-peptide units from the carrier lipid to the growing peptidoglycan acceptor, or to transport lipid-linked intermediates across the forespore membrane.

scholarly journals Association of Alcaligenes Faecalis Strain in Juvenile Earthworms, from Cocoons of Eudrilus Eugeniae

2019 ◽  
Vol 9 (2S2) ◽  
pp. 688-692
Keyword(s):  
16S Rrna ◽  
Gene Sequence ◽  
Agar Medium ◽  
Alcaligenes Faecalis ◽  
Rrna Gene ◽  
Eudrilus Eugeniae ◽  
Zone Of Inhibition ◽  
Chain Reaction ◽  
Nutrient Agar Medium ◽  
Polymerase Chain

Cocoons of earthworm Eudrilus eugeniae were collected from vermiculture bed and found that it had antibacterial activity. The size of zone of inhibition was directly proportional to the size of cocoons examined. Along with nutritious fluid and embryos, culturable bacterial community was found inside the cocoons. Bacterial colonies were isolated from the trails of newly hatched, juvenile worms in the nutrient agar medium and examined. Gram negative, rod shaped bacterium was found to be abundant in the trails of juvenile earthworms. Polymerase chain reaction was performed from this bacterium to amplify the gene of 16S rRNA and analyzed. Subsequent bi-directional DNA sequencing revealed that this abundant bacterium is highly related to 16S rRNA gene sequence of a strain, Alcaligenes faecalis. Based on available literature, we hypothesize that this bacterium could be symbiotically associated with cocoons of earthworms.

Occurrence of Bacillus cereus and the Bacteriological Quality of Chinese “Take-Out” Foods

1978 ◽  
Vol 41 (6) ◽  
pp. 450-454 ◽  
Author(s):  
D. A. SCHIEMANN
Keyword(s):  
Bacillus Cereus ◽  
Nitrate Reduction ◽  
Biochemical Characterization ◽  
Bacteriological Examination ◽  
Bacteriological Quality ◽  
Litmus Milk ◽  
Aerobic And Anaerobic ◽  
Gelatin Hydrolysis

One hundred sixty-five samples of various foods were collected from 24 different Chinese take-out restaurants for bacteriological examination which included enumeration of Bacillus cereus by three media, MYP, KG and blood agars. Blood agar was less selective but no quantitative differences in recovery were apparent. Twenty-eight samples (15%) yielded B. cereus in excess of 100 per gram, and 20 of these were fried rice (33% positive), which also showed the poorest overall bacteriological quality. Biochemical characterization of 232 isolates of B. cereus showed 96% or more positive for catalase, nitrate reduction, beta-haemolysis, subterminal-ellipsoidal spores, aerobic and anaerobic utilization of glucose, Voges-Proskauer, fermentation of glycerol, gelatin hydrolysis, and alkaline peptonization of litmus milk; and a negative reaction in mannitol. Variable results were obtained for motility, fermentation of sucrose and salicin, and starch hydrolysis. Thirty-three isolates were susceptible to 12 of 19 antibiotics tested, and resistant to colistin. Six (18%) were susceptible to penicillin.

Comparison of a simple butterfat agar medium with other media used for isolation and enumeration of lipolytic bacteria from dairy products

1987 ◽  
Vol 54 (3) ◽  
pp. 413-420 ◽  
Author(s):  
Arthur W. Shelley ◽  
Hilton C. Deeth ◽  
Ian C. MacRae
Keyword(s):  
Melting Point ◽  
Bacterial Growth ◽  
Dairy Products ◽  
Agar Medium ◽  
Nutrient Agar ◽  
Nutrient Agar Medium

SummaryA nutrient agar medium containing 0·1 % of a low melting point fraction of butterfat was shown to be suitable for detection, enumeration and isolation of lipolytic bacteria from milk. Bacterial growth was not inhibited by the butterfat and lipolytic reactions were clearly visible and easily interpreted. Lipolytic counts on the butterfat agar compared favourably with lipolytic counts obtained with other commonly used media.

Biochemical characterization of two chitinases from Bacillus cereus sensu lato B25 with antifungal activity against Fusarium verticillioides P03

2020 ◽  
Author(s):  
Estefanía Morales-Ruiz ◽  
Ricardo Priego-Rivera ◽  
Alejandro Miguel Figueroa-López ◽  
Jesús Eduardo Cazares-Álvarez ◽  
Ignacio E Maldonado-Mendoza
Keyword(s):  
Bacillus Cereus ◽  
Biochemical Characterization ◽  
Fusarium Verticillioides ◽  
Expression System ◽  
Phytopathogenic Fungi ◽  
Fungal Cell ◽  
Synthetic Pesticides ◽  
Bacillus Cereus Sensu Lato ◽  
Dual Substrate

Abstract Bacterial chitinases are a subject of intense scientific research due to their biotechnological applications, particularly their use as biological pesticides against phytopathogenic fungi as a green alternative to avoid the use of synthetic pesticides. Bacillus cereus sensu lato B25 is a rhizospheric bacterium that is a proven antagonist of Fusarium verticillioides, a major fungal pathogen of maize. This bacterium produces two chitinases that degrade the fungal cell wall and inhibit its growth. In this work, we used a heterologous expression system to purify both enzymes to investigate their biochemical traits in terms of Km, Vmax, optimal pH and temperature. ChiA and ChiB work as exochitinases, but ChiB exhibited a dual substrate activity and it is also an endochitinase. In this work, the direct addition of these chitinases inhibited fungal conidial germination and therefore they may play a major role in the antagonism against F. verticillioides.

Enumeration of Polyhydroxyalkanoate (PHA) Producing Bacteria from Dairy Sewage Samples

2019 ◽  
pp. 1-4
Author(s):  
K. Shivalkar Yadav ◽  
D. B. Puranik ◽  
Mohamed Nadeem Fairoze ◽  
R. Prabha
Keyword(s):  
Agar Medium ◽  
Synthetic Polymers ◽  
Synthetic Polymer ◽  
Serial Dilution ◽  
Nutrient Agar ◽  
Sewage Sample ◽  
Bacterial Strains ◽  
Nutrient Agar Medium ◽  
Contemporary Life ◽  
Soil And Water

Aims: The synthetic polymer plastics have become an integral part of contemporary life. Excess use of plastics and indiscriminate dumping of it in soil and water is polluting the environment. In order to overcome this problem, the production and applications of eco-friendly biodegradable products from microbes are becoming inevitable from the last decade and also are the good alternatives for synthetic polymers. Methods and Results: Polyhydroxyalkanoate producing bacterial strains were confirmed by serial dilution of sewage samples from dairies and pour plating using modified nutrient agar medium with 2% glucose and 0.3% sudan black. Commercial dairy sewage sample from III Dairy showed highest count of PHA producers (3.80 log10cfu/ml) followed by II Dairy (3.68 log10cfu/ml) and I Dairy (3.35 log10cfu/ml). On an average, 70 per cent were PHA producers among TBC of sewage samples. Conclusion: Dairy sewage sample from III Dairy showed highest count of PHA producers (3.80log10cfu/ml) Significance and Impact of the Study: This study provides importance of polyhydroxyalkanoates and their role against synthetic plastic by enumerating the polyhydroxyalkanoate (PHA) producing bacteria from Dairy sewage samples that can be effectively utilized for the synthesis of bioplastics.

scholarly journals The production and inactivation of pyocines

1963 ◽  
Vol 61 (4) ◽  
pp. 431-441 ◽  
Author(s):  
A. H. Wahba
Keyword(s):  
Sodium Citrate ◽  
Agar Medium ◽  
Proteolytic Enzymes ◽  
Iodoacetic Acid ◽  
Prolonged Storage ◽  
Reference Laboratory ◽  
Laboratory Service ◽  
Dipotassium Hydrogen Phosphate ◽  
Nutrient Agar Medium ◽  
Stable Characteristic

Certain strains ofPs. aeruginosaproduce, in addition to pyocines, substances which inhibit pyocine activity. These pyocine inhibitors are probably proteolytic enzymes.In order to investigate the production of pyocines by various strains ofPs. aeruginosa,aeruginosa, nutrient agar medium was devised in which the action of the pyocine-inhibiting substances is suppressed by incorporating 10–5M iodoacetic acid, 0·1 % sodium citrate and 0·1 % dipotassium hydrogen phosphate. This medium also diminished slime production.Pyocine production is a stable characteristic which is not lost on repeated sub-culture or prolonged storage, and might form the basis of a typing system forPs. aeruginosa.I wish to thank Dr M. T. Parker, Director of the Cross-Infection Reference Laboratory, Public Health Laboratory Service, for constant encouragement and helpful advice.

scholarly journals The Effectivity of Bacteria Isolated From of Liquid Waste Palm Oil Plantation on Ganoderma Boninense

2019 ◽  
Vol 1 (1) ◽  
pp. 1-7
Author(s):  
Fitratul Aini
Keyword(s):  
Palm Oil ◽  
Oil Palm ◽  
Root Rot ◽  
Agar Medium ◽  
Pathogenic Fungus ◽  
Liquid Waste ◽  
Ganoderma Boninense ◽  
Bacterial Isolates ◽  
Basal Stem Rot ◽  
Nutrient Agar Medium

Ganoderma boninense is one of the main pathogenic fungus in oil palm plantations. Generally, these pathogen cause root rot (basal stem rot). Biological control that has been widely used reduce the infection is using bacteria. Liquid waste palm oil has potential to produce bacteria that is able to degrade Ganoderma boninense that causes root rot in oil palm. Liquid waste were obtained from Muaro Sabak Regency Jambi Province. Bacteri were isolated and cultivated in nutrient agar medium, characterized and identified for antagonistic test against G. boninense. Results showed that 16 bacterial isolates were identified, among of them are able to inhibit Ganoderma boninense.

scholarly journals Study of Microbiological Quality of Biscuits from Street Side Bakery Shops at Dehradun City, India

2020 ◽  
pp. 319-326
Author(s):  
Irtiqa Syed ◽  
Rajendra Prasad ◽  
Adeeba Naaz
Keyword(s):  
Agar Medium ◽  
Microbiological Quality ◽  
Nutrient Agar ◽  
Morphological Observation ◽  
Plate Count ◽  
Bacterial Isolates ◽  
Gram Positive ◽  
Gram Positive Bacteria ◽  
Nutrient Agar Medium

<p>In the present study, microbiological quality of biscuits from street side bakery shops at Dehardun city, India was conducted. A total 11 samples of bakery biscuits were collected randomly and analysed for their microbiologically quality by standard plate count method. Pure cultures of bacterial isolates were prepared by streaking on nutrient agar medium. Bacterial isolates were further studied for morphological characters, culture characters on nutrient agar medium and biochemical testes in laboratory. All samples studies were found contaminated by a variety of bacteria. The highest bacterial load was 2.2 ×105 cfu/g and lowest was 0.1×103 cfu/g, respectively. Morphological observation, culture characters and results of biochemical tests of bacterial isolates were compared with standard results of known bacteria. The bacterial isolated were identified as Alcaligenes faecalis, Bacillus cereus, Micrococcus luteus, Pseudomonas aeruginosa, Streptococcus lactis and Staphylococcus aureus, respectively. Among these, two isolates i.e., A. faecalis and P. aeruginosa were gram negative and other isolates were gram positive bacteria which suggested the poor hygienic conditions inside the bakery during preparation and storage of biscuits. Gram positive bacteria might be contaminated during storage and by bad handling. These food spoiling bacteria might be responsible for food-borne infection and diseases. Therefore, care should be taken while purchasing such products and should be purchased from certified bakery shop.</p>

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