121.
A short Communication: Distribution of heterotrophic bacteria in the sediments in the mangrove swamp at Gazi Bay, Kenya
- Boga, HI; Jomo Kenyatta University of Agriculture and Technology, Botany Department, P.O. Box 62000 Nairobi;; Mwatha, WE; Kenyatta University, Botany Department, P.O. Box 43844 Nairobi;
In the first ever study of microorganisms in an East African mangrove swamp, the number of aerobic heterotrophic bacteria in the mangrove swamp sediment was investigated and found to range from 7.44 × 10
6 to 4.70 × 10
8 cfu/g dry wt, (cfu = colony forming units; g dry wt = gram dry weight). The anaerobic heterotrophic bacteria ranged from 7.45 × 10
6 to 1.82 × 10
8 cfu/g dry wt. There was no significant difference between the
Avicennia marina, Ceriops tagal and
Rhizophora mucronata sediments with respect to the number of aerobic and anaerobic bacteria. The exercise was conducted between October...
122.
Antilisterial activity of lactic acid bacteria isolated from vacuum-packaged brazilian meat and meat products
- Martinis,Elaine C.P. De; Públio,Márcia R.P.; Santarosa,Priscila R.; Freitas,Flávia Z.
Twenty samples of Brazilian meat and meat products were screened by the agar overlay method for bacteriocin-producing lactic acid bacteria, using Lactobacillus sake ATCC 15521 as indicator strain. Based on Gram staining, KOH reaction, catalase test and fermentation of 49 carbohydrates (API 50 CH), three out of seven isolates with confirmed antagonist properties were identified as Lactobacillus curvatus, one as Leuconostoc mesenteroides and one as Leuconostoc sp. Two isolates could not be properly identified using these tests. The inhibitors produced by these strains were sensitive to proteases. Inhibition due to lytic bacteriophages was ruled out, so the isolates were classified...
123.
Characterization of five phyllosphere bacteria isolated from Rosa rugosa leaves, and their phenotypic and metabolic properties
- Hashidoko, Yasuyuki; Itoh, Eriko; Yokota, Kentaro; Yoshida, Tadashi; Tahara, Satoshi
Five Gram-negative bacteria, all of which were Enterobacteriaceae, were isolated from the phyllosphere of green or senescing leaves of Rosa rugosa, and their phenotypic and physiological characteristics were examined. Partial 16S rDNA sequences led to identification of these isolates as Pantoea agglomerans, Klebsiella terrigena, Erwinia rhapontici, and two strains of Rahnella aquatilis. Interestingly, these phyllosphere bacteria had certain phenotypic and physiological convergences, while they showed their own metabolic properties toward phenolic compounds of plant origin. In particular, the two Ra. aquatilis isolates from the green leaves had a substrate-inducible gallate decarboxylase activity in the resting cells that had been cultured...
124.
Molecular characterization of intrinsic and acquired antibiotic resistance in lactic acid bacteria and bifidobacteria
- Ammor, Mohammed Salim; Flórez García, Ana Belén; H.A.M. van Hoek, Angela; González de los Reyes-Gavilán, Clara; J.M. Aarts, Henk; Margolles Barros, Abelardo; Mayo Pérez, Baltasar
The minimum inhibitory concentrations (MICs) of 6 different antibiotics (chloramphenicol, clindamycin, erythromycin, streptomycin, tetracycline and vancomycin) were determined for 143 strains of lactic acid bacteria and bifidobacteria using the Etest. Different MICs were found for different species and strains. Based on the distribution of these MIC values, most of the strains were either susceptible or intrinsically resistant to these antibiotics. However, the MIC range of some of these antibiotics showed a bimodal distribution, which suggested that some of the tested strains possess acquired antibiotic resistance. Screening for resistance genes was performed by PCR using specific primers, or using a DNA...
125.
Influência da fonte de carbono e da temperatura sobre a fermentação lática desenvolvida por cultura mista de bactérias láticas
- BALDUINO,Rosicler; OLIVEIRA,Antonio Sérgio de; HAULY,Maria Celia de Oliveira
Bactérias ácido láticas vêm sendo aplicadas em produtos cárneos como culturas iniciadoras. A finalidade das culturas iniciadoras em produtos cárneos é reduzir o pH no início da fermentação O que contribui na inibição de microrganismos indesejáveis, melhorar as propriedades sensoriais, reduzir o tempo de maturação e reduzir nitratos e nitritos. A composição do meio, assim como as condições de cultivo, são importantes para o bom desenvolvimento da cultura iniciadora, sendo necessário conhecer a influência da fonte de carbono e da temperatura no processo fermentativo. O objetivo deste trabalho foi estudar os efeitos da temperatura e de diferentes concentrações de glicose...
126.
Investigation of sulfate-reducing bacteria growth behavior for the mitigation of microbiologically influenced corrosion (MIC)
- Hu, An
SRB in the oil and gas industry have created serious problems. Since the 1980s considerable efforts have been devoted to understanding the corrosion process due to SRB, while the interactions between the biological systems and the environment still remain obscure. A thorough study of the parameters that affect SRB growth with respect to mitigating SRB related MIC is mandatory because the growth behavior of SRB is believed to be an important factor in the MIC process due to SRB. This study focused on the factors influencing the growth of SRB and the corrosion of steel. The ATCC 7757 strain of...
127.
Real-time PCR for quantification of aerobic anoxygenic phototrophic bacteria based on pufM gene in marine environment
- Du HL; Jiao NZ; Hu YH; Zeng YH
The abundance of aerobic anoxygenic phototrophic bacteria (AAPB), a new functional group that plays important roles in marine carbon cycling, is determined frequently by infrared epifluorescence microscopic analysis (IREM) or high-performance liquid chromatography (HPLC) based on detecting BChl a (bacteriochlorophyll a) fluorescence signal at 880 run. Unfortunately, the fluorescence signal is often influenced by environmental variables and physiological state of cell. Here we developed a real-time quantitative PCR (qPCR) assay based on pufM gene to specifically quantify AAPB in marine environments. High specificity and sensitivity for estimation of AAPB abundance were revealed by analysis of amplification products, melting curves and...
128.
An improved method for the determination of NADH oxidase in the presence of NADH peroxidase in lactic acid bacteria
- Talwalkar, Akshat; Kailasapathy, Kasipathy; Hourigan, J.; Peiris, Paul; Arumugaswamy, Ramakrishnaswamy
The complexity of the coupled NADH oxidase–NADH peroxidase enzyme system in lactic acid bacteria makes it difficult to simultaneously determine the individual levels of both these enzymes spectrophotometrically. This study describes an improved assay to accurately determine low concentrations of NADH oxidase from enzyme suspensions containing NADH oxidase and NADH peroxidase. For the standardisation of the assay, pure NADH oxidase and NADH peroxidase were mixed in various proportions and the percentage recovery was estimated by both the currently available assay as well as by the improved assay reported in this study. The recovery of NADH oxidase using the currently available...
129.
An improved method for the determination of NADH oxidase in the presence of NADH peroxidase in lactic acid bacteria
- Talwalkar, Akshat; Kailasapathy, Kasipathy; Hourigan, J.; Peiris, Paul; Arumugaswamy, Ramakrishnaswamy
The complexity of the coupled NADH oxidase–NADH peroxidase enzyme system in lactic acid bacteria makes it difficult to simultaneously determine the individual levels of both these enzymes spectrophotometrically. This study describes an improved assay to accurately determine low concentrations of NADH oxidase from enzyme suspensions containing NADH oxidase and NADH peroxidase. For the standardisation of the assay, pure NADH oxidase and NADH peroxidase were mixed in various proportions and the percentage recovery was estimated by both the currently available assay as well as by the improved assay reported in this study. The recovery of NADH oxidase using the currently available...
130.
Influence of non-sacharomyces yeast growth on the metabolism of nitrogenous compounds in lactic acid bacteria from wine
- Farías,M. E.; Aredes Fernandez,P. A.; Sosa,O. A.; Manca de Nadra,M. C.
A comparative study of the influence of Hanseniaspora uvarum metabolism on the growth and physiology of two lactic acid bacteria involved in vinification: Lactobacillus hilgardii 5w and Oenococcus oeni X2L was carried out. At different yeast growth times in grape juice medium, fermented broth was inoculated with L. hilgardii or O. oeni and incubated for 48 h at 30ºC. When O. oeni grown in the culture supernatant after 0, 3 and 8 hours of yeast growth (M1, M2 and M3 respectively), the growth rate and final biomass were not modified. With L. hilgardii a decrease of both parameters was observed....
131.
Influence of non-sacharomyces yeast growth on the metabolism of nitrogenous compounds in lactic acid bacteria from wine
- Farías,M. E.; Aredes Fernandez,P. A.; Sosa,O. A.; Manca de Nadra,M. C.
A comparative study of the influence of Hanseniaspora uvarum metabolism on the growth and physiology of two lactic acid bacteria involved in vinification: Lactobacillus hilgardii 5w and Oenococcus oeni X2L was carried out. At different yeast growth times in grape juice medium, fermented broth was inoculated with L. hilgardii or O. oeni and incubated for 48 h at 30ºC. When O. oeni grown in the culture supernatant after 0, 3 and 8 hours of yeast growth (M1, M2 and M3 respectively), the growth rate and final biomass were not modified. With L. hilgardii a decrease of both parameters was observed....
132.
Iron bacteria.
- Ellis, David, 1874-1937
xix, 179, [1] p.
133.
Autochthonous lactic acid bacteria from raw milk and soft cheese: screening of bacteriocinogenic cultures, characterization of antagonistic activity and molecular identification
- Maria Beatriz Tassinari Ortolani
A qualidade microbiológica do leite cru brasileiro é reflexo das precárias condições de higiene usualmente observadas em sua produção. Como consequência, esse produto e seus derivados apresentam altas contagens de microrganismos indicadores de higiene, sugerindo a presença de patógenos. Entretanto, devido a sua fraca capacidade de competição, os patógenos sofrem interferência direta da microbiota autóctone desses produtos. Essa interação é confirmada pela baixa ocorrência desses microrganismos em leite e derivados com elevadas contagens de indicadores de higiene. As bactérias ácido láticas (BAL) são os principais componentes da microbiota láctea que determinam essa interferência, pela habilidade de produzir diversas substâncias com...
134.
Role of ionized calcium and magnesium in cellulose degradation by ruminal bacteria
- Morales Silva, Maria Sol
To establish ionized calcium (Ca+2) and magnesium (Mg) requirements for growth (G) and cellulose degradation (CD) by cellulolytic rumen bacteria, F. succinogenes (FS) A3c and S85, R. albus (RA) 7 and 8, and R. flavefaciens (RF) B34b and C94 were incubated with cellobiose for G and cellulose for CD with varying Ca+2 concentrations. Growth was measured at 600 nm and CD by substrate disappearance. Results were analyzed by a logistic function to obtain, max growth (MG), growth rate (GR) and lag time (LT) for G; extent of degradation (ED), degradation rate (DR) and LT for CD. Parameters were analyzed by...
135.
La incorporación de metales pesados en las bacterias y su importancia para el ambiente
- Paula Suárez; Rosa Reyes
Investigación realizada para esclarecer los mecanismos de entrada de metales en las bacterias y la importancia toxicológica de dichos metales.
136.
Identification of exopolysaccharides-producing lactic acid bacteria from Burkina Faso fermented milk samples
- Savadogo, Aly; Laboratoire de Microbiologie et de Biotechnologie . Centre de Recherche en Sciences Biologiques Alimentaires et Nutritionnelles(CRSBAN) UFR/SVT Université de Ouagadougou Burkina Faso 03 BP 7131; aly.savadogo@univ-ouaga.bf; Ouattara, Cheik AT; Laboratoire de Microbiologie et de Biotechnologie . Centre de Recherche en Sciences Biologiques Alimentaires et Nutritionnelles(CRSBAN) UFR/SVT Université de Ouagadougou Burkina Faso 03 BP 7131;; Savadogo, Paul W; Institut de l'Environnement et de la Recherche Agricole (INERA) 01BP476 Ouagadougou, Burkina Faso;; Barro, Nicolas; Laboratoire de Microbiologie et de Biotechnologie . Centre de Recherche en Sciences Biologiques Alimentaires et Nutritionnelles(CRSBAN) UFR/SVT Université de Ouagadougou Burkina Faso 03 BP 7131;; Ouattara, Aboubacar S; Laboratoire de Microbiologie et de Biotechnologie . Centre de Recherche en Sciences Biologiques Alimentaires et Nutritionnelles(CRSBAN) UFR/SVT Université de Ouagadougou Burkina Faso 03 BP 7131;; Traoré, Alfred S; Laboratoire de Microbiologie et de Biotechnologie . Centre de Recherche en Sciences Biologiques Alimentaires et Nutritionnelles(CRSBAN) UFR/SVT Université de Ouagadougou Burkina Faso 03 BP 7131;
Spacer region between 16S and 23 S rRNA genes of thirteen lactic acid bacteria strains from Burkina Faso fermented milk samples were amplified by the polymerase chain reaction (PCR).
Lactobacillus delbrueckii, Lactobacillus acidophilus, Lactobacillus fermentum, Streptococcus thermophilus, Pediococcus spp, Leuconostoc mesenteroides subsp mesenteroides were identified. The
Lactobacillus group was the predominant bacteria. Plasmids identified ranged between 2000 and 4000 bp. Exopolysaccharides (EPS) production varied from 181 mg/l and 814 mg/l, monomer analysis showed that glucose and galactose were predominant.
Key Words: Lactic acid bacteria, fermented milk, PCR, exopolysaccharides.
African Journal of Biotechnology Vol.3(3) 2004: 189-194
137.
The Inhibitory Action of Aqueous Garlic Extract on the Growth of Certain Pathogenic Bacteria
- Astal, Z; Khan Younis Hospital Laboratory, Khan Younis, Gaza-Palestinian Authority.;
This work reports the antibacterial effect of aqueous garlic (
Allium sativum) extract on certain pathogenic Gram positive bacteria,
Staphylococcus aureus, Staphylococcus saprophyticus, Streptococcus pneumonia and
Streptococcus faecalis, and Gram negative bacteria
Escherichia coli, Enterobacter cloacae, Klebsiella pneumonia, Proteus mirabilis, Pseudomonas aeruginosa and
Acinetobacter haemolyticus and determined the optimal conditions for storage of garlic extract. The results have revealed that, a concentration of 750 to 1000 µg/ml of the aqueous garlic extract has high antibacterial effect. Storage for 6 h at 30-50 °C, was found to have optimal efficacy for inhibiting the growth of pathogenic bacteria, while a storage temperature of...
138.
Characterization of the Physical, Chemical, and Biological Factors that Control the Fate and Transport of Bacteria through Glacial-Outwash Sediments
- Mitchell, Beth Louise
This study investigated the effects of sediment grain size distribution, mineralogy and surface charge, and bacterial surface charge on bacterial transport through natural porous media. Bacterial flow-through experiments were conducted using three intact heterogeneous sediment cores. Sediments were characterized for their physical and chemical properties. The surface charge of the suspended bacteria in the influent and effluent was also measured. Results indicated that the presence of dolomite was significant to the fractions of retained bacteria. Surface charge of the effluent bacteria results indicated that the attractive forces between the sediments and bacteria were significant to bacterial transport. The overall results...
139.
Comunicação e movimento ambientalista: bactéria verde dentro da sociedade global
- Porto Vilas, Jean
Nas entranhas da sociedade global, a bactéria verde começa a cristalizar de forma microscópica uma nova maneira de se relacionar com o mundo. Parido dentro da pós-modernidade e contraponto à globalização, o movimento ambientalista nasceu pela e para a mídia. Discurso alternativo hoje, vislumbra-se no ambientalismo idéias que tendem a ser dominantes amanhã. O presente artigo mostra que a comunicação tem e terá papel fundamental no espalhamento da bactéria verde, que pode ser entendida como a disseminação de informações com o poder de alterar o padrão de relacionamento da humanidade com o meio ambiente. No jornalismo, na publicidade, nas estratégias...
140.
Behavior of a psychrotrophic lactic bacteria into different temperatures
- MATAMOROS, S; LEROI, Francoise; PREVOST, H; PILET, M. F.
La souche de Lactococcus sp. EU2241 a été isolée à partir de saumon emballé sous atmosphère modifiée. Elle a montré d'exellentes aptitudes à la biopréservation, augmentant la durée de vie de crevettes décortiquées sous vide, de saumon fumé et permettant d'inhiber de 2 logs la croissance de Listeria monocytogenes et Staphylococcus aureus sur du saumon fumé. L'objectif de ces travaux est de caractériser le comportement à basse température de cette souche, et d'identifier les mécanismes moléculaires intervenant dans sa capacité à s'adapter aux basses températures. Ce travail a été réalisé dans le cadre du projet intégré (IP) SEAFOODplus accordé par...
