GENETIC IMPROVEMENT OF HIGHLY GELLAN GUM PRODUCING STRAINS OF Sphingomonas paucimobilis via PROTOPLAST FUSION

Document Type : Original Article

Authors

1 Microbial Genetic Dept., National Research Center, Cairo, EGYPT

2 Microbial Biotechnology Dept., National Research Center, Cairo, Egypt

Abstract

Three local strains; Sphingomonas paucimobilis Kb1( S.p.Kb1), Sphingomonas paucimobilis CAAS11, (S.p.CAAS11) and Sphingomonas paucimobilis .CAAS6 S.p (CAAS6) were used throughout this investigation to improve their potentialities as gellan gum producers. Three of protoplast fusion experiments were done between the three Sphingomonas paucimobilis local strains; S.p.Kb1 (P1), CAAS6 (P2) and S.p.CAAS11 (P3) at all possible combinations and the fusants were obtained after 1 hr incubation period. Four fusants were obtained after one hour producing gellan gum higher than their parents. The obtained fusant Sp2::Sp3- F4 from the third protoplast fusion experiment P2:: P3  is the best in their gum efficiency rate (two times and half than their parents), followed by the two obtained fusants; Sp1::Sp2- F1 and Sp1::Sp3- F2, from the other two experiments; P1 :: P2 and P1 :: P3, respectively have the same gum efficiency rate, two times than their parents. They have higher viscosity values than that of their parents. All the obtained four fusants have promising economic value and can be used from further genetic improvement.

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