ISSN 2736-1756
Research Article
Advanced Journal of Microbiology Research Vol. 2005
Available online at http://internationalscholarsjournals.org/journal/ajmr
© 2005 International Scholars Journals
Full Length Research Paper
Increase of nisin production by Lactococcus lactis in different media
Angela Faustino Jozala1, Letícia Célia de Lencastre Novaes1, Olivia Cholewa2, Dante Moraes1, Thereza Christina Vessoni Penna1*
1Department of Biochemical and Pharmaceutical Technology School of Pharmaceutical Sciences, University of São Paulo /SP, Brasil.
2Molecular Probes, Inc., Eugene, Or, USA. 97402. Email: [email protected].
Accepted December, 2004
Abstract
Nisin production related to the growth conditions of Lactococcus lactis subsp. lactis ATCC 11454, the effects of various media components and concomitant release of nisin into the media, were studied through transfers (five times). Nisin production was assayed by agar diffusion using Lactobacillus sake ATCC 15521 as the sensitive test organism. The expression of nisin was strongly influenced by the addition of skimmed milk to both MRS and M17 broth, with the highest production obtained after the second and the fifth transfers, respectively, with maximum expression after 36 h of incubation.
Key words: Nisin, Lactococcus lactis, Lactobacillus sake, bacteriocin, milk.
Dante Moraes, LetÃcia Célia de Lencastre Novaes, Angela Faustino Jozala, Thereza Christina Vessoni Penna*, Olivia Cholewa
Page: 1 - 10
Short Communication
Advanced Journal of Microbiology Research Vol. 2005
Available online at http://internationalscholarsjournals.org/journal/ajmr
© 2005 International Scholars Journals
Short Communication
Activity of essential oil and phenolic acid extracts of pepperfruit (Dennetia tripetala G. Barker; Anonaceae) against some food-borne microorganisms
B. O. Ejechi* and D. E. Akpomedaye
Department of Botany and Microbiology,Delta State University, Abraka, NIGERIA
Accepted 28 December, 2004
Abstract
A previous report showed that the essential oil and phenolic acid extracts of pepperfruit (Dennetia tripetala) inhibited the growth of tomato-rot fungi. The study was subsequently extended to other food-borne microorganisms (Staphylococcus aureus, Salmonella sp. Pseudomonas aeruginosa., Proteus sp., Escherichia coli., Enterococcus faecalis., Serratia sp., Bacillus sp., Clostridium sp., Penicillium sp., Aspergillus flavus) isolated from food products. All the isolates were susceptible to the extracts with a minimum inhibitory concentration (MIC) range of 1.0-4.0 mg/ml. The essential oil inhibited the food-borne organisms better (MIC: 1.0-2.5) than the phenolic acid (MIC: 1.5-4.0). The challenge organisms in fresh, boiled or roasted beef, treated with the extracts were either not detected, declined significantly in number (p<0.05) or did not change significantly in population (p>0.05) after 7 days. A role for pepperfruit extracts in natural food protection is further indicated.
Key words: Essential oil, pepperfruit, dennetia tripetala, phenolic acid, food-borne microorganisms.
B. O. Ejechi*, D. E. Akpomedaye
Page: 1 - 10
Short Communication
Advanced Journal of Microbiology Research Vol. 2005
Available online at http://internationalscholarsjournals.org/journal/ajmr
© 2005 International Scholars Journals
Short Communication
Isolation and Identification of a Brevibacterium linens strain degrading p-nitrophenol
Debananda Ningthoujam
Department of Biochemistry Manipur University Canchipur, Imphal 795 003(India). Email: [email protected], [email protected]; Tel: +91(0)385 222 9169; Fax: +91(0) 385 2435 154.
Accepted 26 January, 2005
Abstract
A bacterium was isolated from garden soil in basal salts medium containing p-nitrophenol (PNP). Subsequent subcultures in basal salts agar, nutrient agar plates and agar slants by streaking led to isolation of pure colonies. The pure culture could degrade up to 300 mg/L PNP in presence of yeast extract. It was Gram positive rods, mostly single, catalase-positive, hydrolyzing strach and casein but not urea. Gelatin liquefaction was positive whereas acid production from carbohydrates was negative. It showed tyrosine clearing and had meso-DAP as the characteristic cell wall amino acid. On the basis of the morphological, physiological, and biochemical tests the organism was identified as Brevibacterium linens. To our knowledge, this is the first report of any Brevibacterium strain able to degrade PNP.
Key words: p-Nitrophenol, nitroaromatics, (bio) degradation, isolation, Brevibacterium.
Deban , a Ningthoujam
Page: 1 - 10
Research Article
Advanced Journal of Microbiology Research Vol. 2005
Available online at http://internationalscholarsjournals.org/journal/ajmr
© 2005 International Scholars Journals
Full Length Research Paper
Effect of cultural conditions on xylanase production by Streptomyces sp. (strain Ib 24D) and its potential to utilize tomato pomace
Rifaat Rawashdeh, Ismail Saadoun* and Amjad Mahasneh
*Department of Applied Biological Sciences, Jordan University of Science and Technology, Irbid-22110, Jordan.
Accepted 17 February, 2005
Abstract
The purpose of this study was to determine the effect of some cultural conditions on the xylanase enzyme production by Streptomyces sp. (strain Ib 24D) and to investigate its potential to produce xylanase utilizing tomato pomace as a substrate. Xylanase activity was detected using the dinitrosalicylic acid assay method. The crude enzyme was maximally active at pH 6.5 and 60°C. The maximal enzyme production was obtained when oat spelt xylan was used as a carbon source. When tomato pomace was used as carbon and nitrogen source, the maximal xylanase production was 1447 U/ml. SDS-PAGE and zymogram analysis revealed one band of 58 kDa with xylanolytic activity. The Streptomyces sp . (strain Ib 24D) was able to produce a considerable amount of xylanase with high levels of activity at a broad ranges of pH and temperature, in addition to its ability to utilize tomato pomace as a carbon and a nitrogen source.
Key words: Agricultural wastes, biodegradation, Streptomyces sp., xylanase.
Rifaat Rawashdeh, Ismail Saadoun* and Amjad Mahasneh
Page: 1 - 10
Short Communication
Advanced Journal of Microbiology Research Vol. 2005
Available online at http://internationalscholarsjournals.org/journal/ajmr
© 2005 International Scholars Journals
Short Communication
Quantitative trait loci for head-bug resistance in sorghum
M. Deu1, A. Ratnadass2*, M. A. Hamada2, J.L. Noyer3, M. Diabate2† & J. Chantereau4
1CIRAD-CA, UMR 1096/PIA, TA 40/03, F-34398 Montpellier, France.
2ICRISAT-CIRAD, BP 320 Bamako, Mali.
3CIRAD-AMIS, UMR 1096/PIA, TA 40/03, F-34398 Montpellier, France.
4CIRAD-CA, Programme CALIM, TA 73/09, F-34398 Montpellier, France.
Accepted 23 December, 2004
Abstract
QTLs were mapped in F2 progeny derived from a cross between the head-bug resistant sorghum cultivar Malisor 84- 7 and susceptible S 34. The phenotypic evaluation was conducted in Mali. The mapped population consisted of 217 F2 plants, with 345 homologous and heterologous RFLP probes and 49 microsatellite markers tested. Eighty-one RFLP markers revealed polymorphism between the two parents, and 14 microsatellite markers gave usable amplification products. A genetic map including 92 loci distributed over 13 linkage groups, and covering a total distance of 1160 cM was built. Three significant and seven putative QTLs were detected and placed on the map.
Key words: Head-bug, Eurystylus oldi, sorghum, resistance, RFLP, microsatellite, QTL.
J.L. Noyer, M. Diabate and J. Chantereau, M. Deu, A. Ratnadass*, M. A. Hamada
Page: 1 - 10
Short Communication
Advanced Journal of Microbiology Research Vol. 2005
Available online at http://internationalscholarsjournals.org/journal/ajmr
© 2005 International Scholars Journals
Short Communication
Somatic embryogenesis in date palm (Phoenix dactylifera L.) from apical meristem tissues from ‘zebia’ and ‘loko’ landraces
Chukwuemeka R. Eke1, Peter Akomeah2 and Omorefe Asemota1*
1Physiology Division, Nigerian Institute for Oil Palm Research, P.M.B. 1030, Benin City, Nigeria.
2Botany Department, Ambrose Alli University, Ekpoma, Nigeria.
Accepted February 23, 2005
Abstract
The shoot apical meristem from young suckers were used as sources of explants for initiation of culture using MS basal medium which contained 2,4-D. This was incubated at 27oC in the dark. Callogenesis was observed as early as the second subculture. Continuous subculture of the callus in the establishment medium at about the third subculture from calls production, resulted in somatic embryo formation. The somatic embryos were then transferred to MS medium without hormones under light where they matured after about two subcultures and developed into shoots. The shoots produced roots when transferred to a medium which contained NAA at 0.1 mg/L.
Key words: somatic embryogenesis, date palm, in vitro, micropropagation.
Peter Akomeah and Omorefe Asemota*, Chukwuemeka R. Eke
Page: 1 - 10