Continuing fascination of exploration in natural substances from microorganisms^†

^†This work is a translation of an original work in Japanese in the Japan Society for Bioscience, Biotechnology, and Agrochemistry http://doi.10.1271/kagakutoseibutsu.54.10

Figures & data

Fig. 1. Colonies (A) and scanning electron micrograph of aerial spore chains (B) of the avermectin-producing strain, Streptomyces avermectinius MA-4680^T, grown on agar medium.

Fig. 2. Detection of superoxide anion () generated from GPM agar medium (A), various nutritional media (B), and GPM medium components (C).

Fig. 3. Detection of reactive oxygen species generated from GPM medium.

Table 1. New taxa isolated by agar media supplemented with a scavenger of reactive oxygen species.

Scavenger		SOD	Catalase	SOD +catalase	Ascorbic acid	Rutin
New taxon
New family
Patulibacter minatonensis KV-614^T		1
New genus
Humibacillus xanthopallidus KV-663^T			1
Humihabitans oryzae KV-657^T			1
Oryzihumus leptocrescens KV-628^T, KV-647, KV-656		1	1	1
New species
Arthrobacter humicola KV-651^T				1
Arthrobacter oryzae KV-653^T			1
Demequina salsinemoris KV-810^T, KV-811, KV-816					2	1
Microbacterium aoyamense KV-492^T				1
Microbacterium deminutum KV-483^T				1
Microbacterium pumilum KV-488^T				1
Microbacterium pygmaeum KV-490^T				1
Microbacterium terricola KV-448^T		1
*Conexibacter arvalis KV-962^T, KV-963

Notes: Soil samples: Field and paddy field in Saitama prefecture, Bank in Tokyo, Amamioshima island.

*Isolated with Nutrient agar (Difco) diluted fivefold, for 21 days cultivation.

Fig. 4. Taxonomical characteristics of Patulibacter minatonensis KV-614^T.

Fig. 5. New genera and new species of actinomycetes isolated from plant roots.

Table 2. Compounds discovered by physicochemical screening and their biological activities.

	Compound	Year discovered	Producing microorganism	Biological activity (Year)
Doragendorff’s reaction	Pyrindicin	1973	Streptomyces griseoflavus NA-15^T	Antimicrobial (1973)
	NA-337A	1974	Streptomyces sp. NA-377	Hypolipidemic (1974)
	TM-64	1975	Thermoactinomyces antibiotics TM-64	Deteriorated reflex of the cornea (1975)
	Quinoline-2-methanol	1976	“Kitasatoa griseophaeus” PO-1227^T	Hypoglycaemic (1976)
	Dityromycin	1977	Streptomyces sp. AM-2504	Antimicrobial (1977), Inhibition of EF-G (2014)
	Staurosporine	1977	Lentzea albida AM-2282	Antifungal and Antitumor (1977), Inhibition of protein kinases (1986)
	1,3-Diphenethylurea	1978	Streptomuces sp. AM-2498	Antidepressant (1978), Adipocyte differentiation promoter (2011)
	Herquline	1979	Penicillium herquei Fg-372	Herquline B; Inhibition of platelet aggregation (1996)
	Neoxaline	1979	Aspergillus japonicus Fg-551	Inhibition of tubulin polymerization (1974)
	Reductinomycin	1981	Streptomyces xanthochromogenus AM-6201	Antitumor, Antibacterial and Antivirus (1981)
	Sespendole	2004	Pseudobotrytis terrestris FKA-25	Inhibition of cholesteryl ester and triacylglycerol, Antimicrobial (2006)
	Spoxazomicin	2011	Streptosporangium oxazolinicum K07-0460^T	Anti-trypanosomal activity (2011)
LC/UV-MS	Actinoallolide	2011	Actinoallomurus fulvus MK10-036	Anti-trypanosomal activity (2011)
	Mangromicin	2011	Lechevalieria aerocolonigenes K10-0216	Anti-trypanosomal activity (2011), Antioxidative activity (2013)
	Trehangelin	2012	Polymorphospora rubra K07-0510	Anti-Lipid peroxidation (2013)
				Enhanced production of collagen (2014)
	Iminimycin	2015	Streptomyces griseus OS-3601	Antimicrobial (2015)
	Sagamilactam	2015	Actinomadura sp. K13-0306	Anti-tripanosonal activity (2015)

Notes: Reference, splendid gift from microorganisms – the achievement of Satoshi Ōmura and colladorators – 5th edition (2015).

Fig. 6. Structure of iminimycin A.