Lysobacter, a New Genus of Nonfruiting, Gliding Bacteria with a High Base Ratio

Highly mucoid, cream, pink and yellow-brown gliding organisms having deoxyribonucleic acid guanine-plus-cytosine contents of 62 to 70.1 mol% have been isolated by several workers, but since these organisms have never been observed to produce typical myxobacterial fruiting bodies, their taxonomy has been problematical. Forty-six isolates were studied in detail, among them Ensign and Wolfe's organism AL-1 and Cook's isolate 495, both of which produce important proteases, as well as Cook's culture 3C, which elaborates the potent, wide-spectrum antibiotic myxin. A new genus, Lysobacter, has been established for these organisms, and four new species and one new subspecies have been named and described: L. antibioticus (type strain, ATCC 29479), L. brunescens (type strain, ATCC 29482), L. enzymogenes (type strain, ATCC 29487), L. enzymogenes subspecies cookii Christensen (type strain, ATCC 29488), and L. gummosus (type strain, ATCC 29489). The dimensions of the thin, gliding, flexing cells of Lysobacter are 0.3 to 0.5 by 1.0 to 15.0 (sometimes up to 70) μm. These soil and water organisms all degrade chitin, two degrade alginate, three degrade pectate, three degrade carboxymethylcellulose, and one degrades starch, but none decomposes filter paper or agar. They are strongly proteolytic and characteristically lyse a variety of microorganisms such as gram-negative, gram-positive (including actinomycetes), and blue-green bacteria, fungi, and green algae, as well as nematodes. The genus has been placed in a new family, Lysobacteraceae, within a new order, Lysobacterales.