Aims Biological techniques can manage plant diseases safely and in environmentally friendly ways, but their efficacy needs improvement. It is of the utmost importance to search for powerful microbes for the effective control of plant diseases. Methods and Results Unheated self‐digestive solutions (SDS) that were heated at 100°C for 30 minutes (H‐SDS) or stored for 12 months at room temperature (S‐SDS) were prepared from Lysobacter enzymogenes LE16 broth culture to study their potential as biocontrol agents. This bacterium produced protease, phosphatase, lysozyme, and siderophores in pure culture as well as 12 secondary metabolites including novel antibiotics lysobactin, WAP‐8294A₂, and mupirocin determined based on the antiSMASH 5.0.0 BLAST database. A poison plate assay revealed the antagonistic activities of SDS, H‐SDS, and S‐SDS against an animal pathogenic bacterium Staphylococcus aureus , a phytopathogenic bacterium Pseudomonas syringae pv. tabaci , and numerous plant pathogenic fungi and oomycetes, including Colletotrichum gloeosporioides , Penicillium italicum , Alternaria alternate , Rhizoctonia solani , Didymella bryoniae , Sclerotinia sclerotiorum , Phytophthora nicotiana , and Phytophthora capsici . The greenhouse experiment showed that SDS was highly effective in controlling pepper blight disease, which is caused by P. capsici . Compared with only pathogen inoculation, the application of SDS to the soil in preventive or curative treatments significantly reduced the disease incidence and index with relatively high control efficacy of 86.2–93.1%. Conclusions SDS enriched lytic enzymes, siderophores, and antibiotics, has a wide antimicrobial spectrum, and shows potential as a new, safe, and effective biocontrol agent against plant diseases. Significance and Impact of the Study Autolysates of the new biocontrol bacterium L. enzymogenes LE16 demonstrated the potential for industrial production and commercial use as a promising biocontrol agent in agriculture.

A rotation of summer tobacco–winter barley–next summer maize (T-B-M) has been suggested by Chinese government programs as an alternative land use practice to replace the conventional tobacco–fallow monoculture (T) and tobacco–barley succession (T-B) management systems. Crop yield in each crop system was recorded from 2010 to 2016 and routine and 454 pyrosequencing approaches were used to evaluate the effects of these cropping systems on organic matter, enzyme activity, and bacterial biomass and community composition within the same soil type. Tobacco leaf yields, barley grains, organic matter, microbial biomass, and enzyme activity (urease, neutral phosphatase, invertase and dehydrogenase) in the soil increased with crop species (but differences were not significant for dehydrogenase activity between T and T-B, and for neutral phosphatase activity between T-B and T-B-M). Indices of richness and diversity of soil bacterial communities also increased as the number of 16S rRNA gene sequences and bacterial phylotypes in the soil increased. The presence of many different bacteria in a soil system may prevent excess reproduction of any single pathogenic bacterium and subsequently reduce the risk of large-scale disease spread. All cropping soils were dominated by Proteobacteria, Acidobacteria, Actinobactria, Bacteroidetes, and unclassified bacteria. Of the 20 predominant bacteria, 13 were commonly found in all soils studied, whereas only four to five were unique in each of the soils examined. This suggests that the presence of those bacteria was more influenced by soil properties than cropping systems in a period of land use.