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[en] This paper summarized the achievements and developments in mutation breeding and genetic research of soybean. The optimal irradiation dosage was determined for 22 varieties of soybean which have been released and popularized so far. Analyses of mutants, mutant characters and mutation frequency in the generations of M₁, M₂ and M₃ of soybean were carried out and a procedure of mutation breeding was described. Discussion of the effect of different radiant agents, the selection of progeny induced by radiation, the breeding method by combining mutation with hybridization and resistant varieties with good quality ones have been conducted

[en] The experiment showed that the highest protein and fat contents in M₂ and M₃ mutant groups were 2.6% and 2.15% for protein, and 0.59% and 0.49% for fat, respectiyely, up on that of controls. Mutagenic effect of protein is better than that of fat. Mutagenic effects could be observed in 17 kinds of amino acid and 5 kinds of lipid acids, especially in methionine and linolenic acid. The highest methionine content in mutagenic groups was increased by 91% compared with that of control and the content of linolenic decreased by 0.18 to 0.70% with a frequency of 30%. The correlations between 17 kinds of amino acid and protein contents and between 6 kinds of lipid acid and oil contents were evaluated respectively to supply the reference for improving the nutritional quality of summer soybean in breeding and field selection

[en] Highlights: • Record efficiency was achieved for phthalate ester degradation by strain BJQ0005. • Whole metabolic pathway was proposed using genome sequence and intermediate analysis. • Three hydrolases were identified with one di-ester bond hydrolysis enzyme. • Mechanism affecting enzymatic ester hydrolysis of mono-ester phthalate was proposed. Phthalate ester pollution in the environment and food chain is frequently reported. Microbial treatment is a green and efficient method for solving this problem. The isolation and systematic investigation of microorganisms generally recognized as safe (GRAS) will provide useful resources. A GRAS Bacillus subtilis strain, BJQ0005, was isolated from Baijiu fermentation starter and efficiently degraded phthalate esters (PAEs). The half-lives for di-isobutyl phthalate, di-butyl phthalate and di-(2-ethylhexyl) phthalate were 3.93, 4.28, and 25.49 h, respectively, from the initial amount of 10 mg per 10 mL reaction mixture, which are records using wild-type strains. Genome sequencing and metabolic intermediate analysis generated the whole metabolic pathway. Eighteen enzymes from the α/β hydrolase family were expressed. Enzymes GTW28₀9400 and GTW28₁3725 were capable of single ester bond hydrolysis of PAEs, while GTW28₁7760 hydrolyzed di-ester bonds of PAEs. Using molecular docking, a possible mechanism affecting enzymatic ester bond hydrolysis of mono-butyl phthalate was proposed of GTW28₁7760. The carboxyl group generated by the first hydrolysis step interacted with histidine in the catalytic active center, which negatively affected enzymatic hydrolysis. Isolation and systematic investigation of the PAE degradation characteristics of B. subtilis will promote the green and safe treatment of PAEs in the environment and food industry.