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Low-energy ion beam implantation (10 ~ 200 keV) has been proved to have a wide range of biological effects and is broadly used in the breeding of crops and micro-organisms.To understand its mechanisms better and facilitate its applications, the developments in the bioeffects of low energy ion beam implantation in the past twenty years are summarized in this paper.

Mutant strains of GO112 and BM302 with a high 2-keto-L-gulonic acid (2KLG) transformation rate induced by ion beam implantation were separately and combinatorially compared with the original strains GO29 and BM80 to study the mutagenic effects of ion beam implantation. Both the sole GO112 and mixed BM302:GO112 demonstrated improved SNDH activity and 2KLG yield compared to the original strains. The mutant combinations of BM302:GO112 showed a longer stationary phase and higher biomass than BM80:GO29. The mutant BM302 exhibited a stronger capacity to maintain a stable pH environment at mixed fermentation with Gluconobacter oxydans (G. oxydans) for 2KLG transformation and facilitated the growth of G. oxydans compared with the original strain BM80. The promotive capacity to L-sorbosone dehydrogenase (L-SNDH) from the supernate of BM302 was 1.6-fold higher than that of BM80. Genes encoded SNDH in GO29 and GO112 were amplified and sequenced, and mutations including three transitions (CG → TA, CG → TA, GC → AT) and one transversion (AT → TA) were confirmed from GO29 to GO112. The corresponding amino acid was changed as Leu → Phe, Arg → Gln and Asn → Lys.