MOSP - Macao Scientific Publishers

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Production of poly-hydroxybutyrate (PHB) and differentiation of putative Bacillus mutant strains by SDS-PAGE of total cell protein

Hikmet Katırcıoğlu*, Belma Aslım, Zehra Nur Yüksekdað, Nazime Mercan, Yavuz Beyatlı

Abstract: In this study, the putative mutant strains of Bacillus megaterium Y6, B. subtilis K8, B. sphaericus X3 and B. firmus G2 were studied for their poly- -hydroxybutyrate (PHB) production capacities. Mutations were induced by using UV light, acriflavin and 5-bromourasil. Total cell proteins were extracted from 59 strains and compared using SDS-PAGE. For each strain, percentage yield of PHB according to cell dry weight was determined in a range of 1.46-63.45%. PHB production of 8 mutant strains were found to increase in comparison with parental strains. However, no increase in PHB production of mutant strains of B. sphaericus X3 was found. It was also determined that the protein profiles of the mutant strains with high PHB yield generally differed from the protein profiles of parental strains.[...] Read More.

Keywords: Bacillus, poly- -hydroxybutyrate, PHB, total cell protein.

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Bacillus pumilus BpCRI 6, a promising candidate for cellulase production under conditions of catabolite repression

Kotchoni O.S.*†, Shonukan O.O. and Gachomo W.E.

Abstract: Cellulose degrading organisms have been used for the conversion of cellulolytic materials into soluble sugars or solvents in several biotechnological and industrial applications. In this report, a mutant of Bacillus pumilus was obtained after chemical mutagenesis and screened for cellulase production. This mutant named BpCRI 6 was selected for its ability to produce cellulase under catabolite repression. Cellulase yield by BpCRI 6 was four times higher than that of the wild type under optimum growth conditions (pH 6.5, 25°C and Ca2+ 1mM). In shaking flask cultures, production of cellulase by the wild type was completely repressed in the presence of 25 mM glucose, while BpCRI 6 strain still exhibited a residual cellulase production of 80 and 40% at 25 mM and 40 mM of glucose concentrations respectively. The mutant strain is stable and grows rapidly in liquid and solid media. Under conditions of catabolite repression (40 mM of glucose), the production of cellulase by this mutant is particularly significant when compared to Trichoderma reesei a well-known cellulase producer, which is under control of end-product inhibition. This is the first report of a successful catabolite repression insensitivity of cellulase production by a mutant of B. pumilus.[...] Read More.

Keywords: Cellulase, Bacillus pumilus, BpCRI 6, Catabolite repression.

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DNA Sequences of RAPD Fragments in the Egyptian cotton Gossypium barbadense

Abdel Ghany A. Abdel Ghany and Essam A. Zaki,*

Abstract: Random Amplified Polymorphic DNAs (RAPDs) is a DNA polymorphism assay based on the amplification of random DNA segments with single primers of arbitrary nucleotide sequence. Despite the fact that the RAPD technique has become a very powerful tool and has found use in numerous applications, yet, the nature of molecular variation(s) uncovered by the RAPD technique is still unclear. The aim of the following study, therefore, was to investigate the molecular nature of RAPD DNA fragments in four Gossypium barbadense cultivars. Five RAPD DNA fragments, generated by improved RAPD-PCR technique, and representing polymorphic and nonpolymorphic bands were analyzed at the molecular level using DNA sequence analysis. Nonpolymorphic RAPD DNA fragments showed homologies to previously characterized plant structural genes. Comparative nucleotide sequence analysis of two comigrating nonpolymorphic fragments revealed that these two DNA sequences are highly similar to each other, indicating that similarity of fragment size is a good predicator of homology. Polymorphic RAPD DNA fragments, on the other hand, showed homologies to middle and high-repetitive DNA sequences. These results promote the initiative to integrate these RAPD markers in cotton breeding applications, and DNA fingerprinting.[...] Read More.

Keywords: Gossypium, MITEs, RAPD-PCR, repetitive DNA, sequence similarity, retrotransposons.

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Molecular distribution of gypsy-like retrotransposons in cotton Gossypium Spp.

Essam A. Zaki* and Abdel Ghany A. Abdel Ghany

Abstract: PCR primers specific for conserved domains of the reverse transcriptase (RT) genes of gypsy-like retrotransposons amplified their corresponding gene in two Gossypium barbadense cultivars. Analysis with the FASTA software showed a high DNA sequence homology to pine, gypsy LTR-retrotransposon. Using the PCR product as a hybridization probe, gypsy-like retrotransposons were detected in wild type species of Gossypium, suggesting that gypsy-like retrotransposons are present in the Gossypium genome. This supports the view that gypsy-like retrotransposons are major components of plant genomes. Our results suggest gypsy-like retrotransposons have played a fundamental role in the shaping and evolution of the Gossypium genome.[...] Read More.

Keywords: Gossypium, gypsy, polyploidy, retroelements, retrotransposons, retroviruses, reverse transcriptase.

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Four gene introduction methods affect the shoot regeneration and localization of transgene expression in greenhouse stem explants and in vitro-grown chrysanthemum stem thin cell layers

J. A. Teixeira da Silva* and S. Fukai

Abstract: Gene introduction method (GIM) affected shoot regeneration capacity (SRC) in standard and spray-type chrysanthemums. SRC was both cultivar and GIM-dependent in both in vitro and greenhouse stem explants, the former significantly higher than the latter. Sonication had an SRC-stimulating effect on in vitro explants. Other GIMs (Agrobacterium, biolistics, Agrolistics) had an SRC-inhibiting effect on greenhouse explants. Genotype-dependence of SRC was observed in both in vitro and greenhouse material. SRC is influenced by the explant and regeneration media, which should be modified if altered by the GIM. Shoots derived from all GIM treatments showed normal growth under in vitro and greenhouse conditions, and flowered normally. In addition, this study further shows that explant origin (in vitro versus greenhouse) and cultivar significantly affect the regeneration process, even when an optimized medium is utilized. The integration of the GUS transgene is also GIM-dependent, but in all cases is shown to occur in the venation. Keywords: Agroinfection, biolistics, explant survival, regeneration, sonication.[...] Read More.

Keywords: Agroinfection, biolistics, explant survival, regeneration, sonication.

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Genetic affinities of Fusarim spp. and their correlation with origin and pathogenicity

Mohmed S. Khalil, Mohmed A. Abdel-Sattar, Ibrahim N. Aly, Kamel A. Abd-Elsalam,* and Joseph A. Verreet

Abstract: Random amplified polymorphic DNA (RAPD) analyses was used in combination with pathogenicity assays to study the taxonomic kinships among five Fusarium species. A total of 46 isolates of Fusarium spp. obtained from diseased cotton seedlings showing typical root rot and dampping-off symptoms were characterized. Of 10 primers tested, four primers produced polymorphic amplification patterns with taxon-specific bands, in addition to individual- specific bands. Genetic analysis indicated into 2 main clusters, with the minor cluster included all F. moniliforme and F. solani at the genetic similarity of GS=57.82%. The major cluster consisted of all F. oxysporum, F. avenaceum and F. chlamydosporum clustered at 71% similarity. There was no clear-cut relationship between clustering in the RAPD dendrogram, pathogenicity test and geographic origin of tested isolates. The results suggest that RAPD-PCR is a useful method for analysing genetic variation within and between Fusarium spp.[...] Read More.

Keywords: DNA-fingerprinting, Fusarium chlamydosporum, genetic homology, RAPD-PCR.

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Substrate Channelling and Energetics of Saccharomyces cerevisiae DSM 2155 Grown on Glucose in Fed-Batch Fermentation Process

Olusegun Peter AKINYEMI, Eriola BETIKU+*, and Bamidele Ogbe SOLOMON

Advanced Journal of Microbiology Research Vol. 2003

Available online at http://internationalscholarsjournals.org/journal/ajmr

Substrate Channelling and Energetics of Saccharomyces cerevisiae DSM 2155 Grown on Glucose in Fed-Batch Fermentation Process

Olusegun Peter AKINYEMI¹, Eriola BETIKU^2+*, and Bamidele Ogbe SOLOMON²

¹Chemical and Polymer Engineering Department, Lagos State University, Lagos State, Nigeria.

²Chemical Engineering Department, Obafemi Awolowo University, Ile-Ife, Osun State, Nigeria.

Accepted 10 April, 2003

Data collected during high-cell-density cultivation of Saccharomyces cerevisiae DSM 2155 on glucose in a simulated five-phase feeding strategy of fed-batch process, executed on the Universal BIoprocess CONtrol (UBICON) system using 150L bioreactor over a period of 24h have been analysed. The consistency of the data set was checked using both the available electron and carbon balances. Estimates of the true energetic yields and cell maintenance requirements were obtained through the application of a multivariate statistical procedure known as covariate adjustment technique. A low value of maintenance coefficient, m_e = 0.004h^-1, and a high average value of the true biomass energetic yield, _max = 0.745, were obtained for the bioreactor system, which showed that the organism was in no danger of ethanol produced during this cultivation. A simple model for estimating the distribution of substrate consumed between the fermentative and the respiratory pathways in the oxido-reductive process was developed based on the respiratory quotient (RQ) values. The fraction of substrate consumed for respiratory metabolic activities (q_sresp/q_s) was virtually 1.0 for the first three phases of the feeding strategy, which accounted for the first sixteen hours of the 24h operation. This was an indication that ethanol formation was avoided during this period.

Key Words: Saccharomyces cerevisiae DSM 2155, available electron and carbon balances, fed-batch, respiratory quotient, true energetic yields, maintenance requirement.

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Bioinformatic tools and guideline for PCR primer design

Kamel A. Abd-Elsalam

Abstract: Bioinformatics has become an essential tool not only for basic research but also for applied research in biotechnology and biomedical sciences. Optimal primer sequence and appropriate primer concentration are essential for maximal specificity and efficiency of PCR. A poorly designed primer can result in little or no product due to non-specific amplification and/or primer-dimer formation, which can become competitive enough to suppress product formation. There are several online tools devoted to serving molecular biologist design effective PCR primers. This review intends to provide a guide to choosing the most efficient way to design a new specific-primer by applying current publicly available links and Web services. Also, the purpose here is to provide general recommendations for the design and use of PCR primers.[...] Read More.

Keywords: Bio-computing, primer design, web-based resources.

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A home made kit for plasmid DNA mini-preparation

Simeon Oloni KOTCHONI , Emma Wanjiru GACHOMO, Eriola BETIKU, and Olusola Olusoji SHONUKAN

Abstract: Many methods have been used to isolate plasmid DNA, but some of them are time consuming especially when extracting a large number of samples. Here, we developed a rapid protocol for plasmid DNA extraction based on the alkaline lysis method of plasmid preparation (extraction at pH 8.0). Using this new method, a good plasmid preparation can be made in approximately one hour. The plasmids are suitable for any subsequent molecular applications in the laboratory. By applying the recommendations to avoid contaminations and to maximize the plasmid yield and quality during extraction, this protocol could be a valuable reference especially when analyzing a large number of samples.[...] Read More.

Keywords: Plasmid extraction, PCR, restriction enzymes, sequencing, contamination.

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Genetic comparisons of Egyptian date palm cultivars (Phoenix dactylifera L.) by RAPD-PCR

Said Saad Soliman, Bahy Ahmed Ali*, Mohamed Morsy Mohamed Ahmed

Abstract: Random amplified polymorphic DNA technique was used to compare genetic material from four females date palm and four unknown male trees of Egyptian date palm. The genetic similarity between the four females date palm (Zaghloul, Amhat, Samany and Siwi) ranged from 87.5 to 98.9%. The banding profiles obtained suggested that both males 3 and 4 are genetically related to the four female cultivars.[...] Read More.

Keywords: Date palm, cultivars, RAPD-PCR, genetic similarity.

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