Biotransformation of 4-sec-butylphenol by Gram-positive bacteria of the genera Mycobacterium and Nocardia including modifications on the alkyl chain and the hydroxyl group

Abstract

The environmental pollutant 4-sec-butylphenol (4-sec-BP) which possesses estrogenic properties was transformed by the aerobic Gram-positive bacteria Mycobacterium neoaurum and Nocardia cyriacigeorgica into three main products (P1-P3) which were isolated and structurally characterized in detail. Two of them were products of a process resembling anaerobic metabolism of alkylphenols based on modifications of the alkyl side chain of 4-sec-BP. The first product (P1) was identified as 4-(2-hydroxy-1-methylpropyl)-phenol. The second product P2 was isolated as a mixture of at least four structures which could be identified as I 4-sec-butylidenecyclohexa-2,5-dienone; II 4-(1-methylenepropyl)-phenol; III 4-(1-methylpropenyl)-phenol; and IV 4-(1-methylallyl)-phenol. In contrast to P1 and P2, the third product (P3) resulted from a modification of the hydroxyl group of 4-sec-BP. This product was only formed by M. neoaurum and was identified as the glucoside conjugate 4-sec-butylphenol-α-D-glucopyranoside. Since in general, fungi synthesize sugar conjugates to detoxify hazardous pollutants, the formation of this conjugate is a peculiarity of M. neoaurum. Thus, altogether, six products were formed from 4-sec-BP and different transformation pathways are introduced. The hydroxylating and glucosylating capacity of the characterized bacteria open up applications in environmental protection.

The ΦBT1 large serine recombinase catalyzes DNA integration at pseudo-attBsites in the genusNocardia

“…Nocardia species are actinomycetes that have features in common with pathogens and secondary metabolite producers. For example, several species of Nocardia (i.e., Nocardia asteroides , Nocardia brasiliensis ) are opportunistic human and animal pathogens, causing lung, skin and brain infections, predominantly in immunocompromised hosts, while others are reservoirs of bioactive natural products ( Hoshino et al, 2011 ; Tanaka et al, 1997 ) and are capable of degrading or converting widespread environmental pollutants ( Hahn et al, 2013 ; Santillan et al, 2016 ). These beneficial properties and their potential biotechnical applications have attracted a great deal of interest in the genus Nocardia.…”

Peer Review #1 of "The ΦBT1 large serine recombinase catalyzes DNA integration at pseudo-attB sites in the genus Nocardia (v0.1)"

“…For example, several species of Nocardia (i.e. Nocardia asteroides, Nocardia brasiliensis) are opportunistic human and animal pathogens, causing lung, skin and brain infections, predominantly in immunocompromised hosts, while others are reservoirs of bioactive natural products (Hoshino et al 2011;Tanaka et al 1997) and are capable of degrading or converting widespread environmental pollutants (Hahn et al 2013;Santillan et al 2016). These beneficial properties and their potential biotechnical applications have attracted a great deal of interest in the genus Nocardia.…”