Construction of engineering bacteria degrading residual polyacrylamide in coal slime water by protoplast fusion technique

Doubly auxotrophic, actinomycin-producing and nonproducing strains of Streptomyces parvulus were crossed by protoplast fusion. A strong bias toward the act+ character was noted in all recombinant classes obtained. Analysis of four nutritonal markers revealed that they are ordered on a circular linkage map as follows: ura-lys-met-rib-(ura). This sequence resulted in the lowest frequency (2.4–3.4%) of quadruple crossover (QCO) recombinants. Inclusion of the property of actinomycin production in this sequence resulted in a much greater minimum frequency of QCO recombinants (3–4 times higher). Moreover, the location of the act character minimizing the QCO frequency varied from cross to cross despite the fact that fusion of the act− strains did not yield act+ recombinants. It is concluded that actinomycin synthesis is determined (or controlled) by an episomic factor(s).

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Isolation and partial characterization of plasmids found in three Halobacterium volcanii isolates

Canadian Journal of Microbiology ◽

10.1139/m89-014 ◽

1989 ◽

Vol 35 (1) ◽

pp. 92-95 ◽

Cited By ~ 11

Author(s):

Ilan Rosenshine ◽

Moshe Mevarech

Keyword(s):

Key Words ◽

Protoplast Fusion ◽

Repetitive Sequences ◽

Partial Characterization ◽

Restriction Maps ◽

Chromosomal Dna ◽

Fusion Technique ◽

Homologous Sequences ◽

Halobacterium Volcanii

Three new isolates of Halobacterium volcanii were screened for the presence of plasmids. Each of the different isolates was found to contain one plasmid. These plasmids do not show any homology to each other, nor to the previously isolated plasmid pHV2. Partial restriction maps of these plasmids were determined. One of the plasmids contains chromosomal repetitive sequences as judged by the existence of homologous sequences in the chromosomal DNA of the three isolates. Using the protoplast fusion technique, we showed that at least one of the newly isolated plasmids is compatible with pHV2.Key words: Halobacterium volcanii, archaebacterium, plasmids.

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High-Yield Laccase-Producing Strains Constructed by Protoplast Fusion Between Bacterium and Fungus

The Open Biotechnology Journal ◽

10.2174/1874070701509010221 ◽

2015 ◽

Vol 9 (1) ◽

pp. 221-224 ◽

Cited By ~ 1

Author(s):

Lihong Zhao ◽

Wenli Yin ◽

Lele Wang

Keyword(s):

Escherichia Coli ◽

Environmental Pollution ◽

Protoplast Fusion ◽

Parental Strain ◽

Pleurotus Ostreatus ◽

Laccase Activity ◽

High Yield ◽

Promising Technique ◽

Fusion Technique ◽

Different Characteristics

This study is based on the construction of high-yield laccase-producing fusant achieved by inter-kingdom protoplast fusion between Pleurotus ostreatus and Escherichia coli. The optimized protoplasts formation and regeneration conditions were demonstrated with the presence of 1.5% cellulase +1.0% snailase and 0.6M mannitol at 30°C for 3h. The fusants were screened for different characteristics between two parental strains and further identified by laccase activity, offering one of the genetically stable fusants, Strain F. The fusant F produced the highest yield of laccase, being about 22% higher than that of the parental strain. The results suggest that the protoplast fusion technique can be considered as a promising technique for the control of environmental pollution.

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