Biodegradation of alkali lignin by a newly isolated Rhodococcus pyridinivorans CCZU-B16

Abstract

Based on the Prussian blue spectrophotometric method, one high-throughput screening strategy for screening lignin-degrading microorganisms was built on 24-well plate at room temperature. One high activity of alkali lignin-degrading strain Rhodococcus pyridinivorans CCZU-B16 was isolated from soil. After the optimization of biodegradation, 30.2% of alkali lignin (4 g/L) was degraded under the nitrogen-limited condition (30/1 of C/N ratio; g/g) at 30 °C for 72 h. It was found that syringyl (S) units and guaiacyl (G) in lignin decreased after biodegradation. Moreover, the accumulated lipid in cells had a fatty acid profile rich in C16 and C18 with four major constituent fatty acids including palmitic acid (C16:0; 22.4%), palmitoleic acid (C16:1; 21.1%), stearic acid (C18:0; 16.2%), and oleic acid (C18:1; 23.1%). In conclusion, Rhodococcus pyridinivorans CCZU-B16 showed high potential application in future.

Recent advances in lignin valorization with bacterial cultures: microorganisms, metabolic pathways, and bio-products

“…Thus, when the culture broth of candidate bacteria was mixed with ABTS solution, the laccase-producing strains can be easily distinguished [29]. In another case, Chong and co-workers screened lignin degradation microbes based on the sensitive prussian blue spectrophotometric method [34]. When K 3 Fe(CN) 6 and FeCl 3 are mixed with phenolic hydroxyl groups, prussian blue is formed because of the redox reaction.…”

“…SHC1Soils of 0–10 cm depths from palm oil plantationPrimary screening by using kraft lignin as the sole carbon source; secondary screening by determining the decolorization of methylene bluePossess high manganese peroxidase activity and lignin peroxidase activity[33]Actinobacteria Streptomyces sp. Y-8Soil samplesEnrich bacteria in mineral salts medium supplemented with lignin as the sole carbon sourcePossess high laccase activity and lignin peroxidase activity[148] Rhodococcus opacus PD630 (DSM 44193)Soils from a gas-works plantEnrich bacteria in mineral salts medium supplemented with phenyldecane as the sole carbon sourceCan accumulate up to 87% (w/w) lipid in cell[149] Rhodococcus jostii RHA1Soils contaminated by γ -hexachlorocyclohexaneEnrich bacteria in mineral salts medium supplemented with biphenyl as the sole carbon sourceCan break down some polychlorinated biphenyl congeners into smaller molecules[150] Rhodococcus pyridinivorans CCZU-B16Soil sampleUse a high-throughput screening strategy using Prussian blue spectrophotometric methodCan convert alkali lignin into microbial lipids[34]–, not mentioned in the paper…”

Bioprospecting Microbial Diversity for Lignin Valorization: Dry and Wet Screening Methods

“…The types of substrates as well as the enzymatic activity related to them are summarized in Table 1. Their advantage in comparison to dyes is the possibility of quantifying the enzyme activity and of developing high-throughput screening assays (Vasilchenko et al, 2012;Chong et al, 2018;Xu et al, 2019). The Prussian blue assay is an example of a colorimetric assay used for addressing lignin-degrading bacteria such as Rhodococcus pyridinivorans and Rhodococcus opacus (Vasilchenko et al, 2012;Xu et al, 2019).…”

Biotechnological potential of fungi and bacteria with ligninolytic activity (mini-review)

“…The third approach is the creation of highly efficient multiple analysis and strain search systems with specified characteristics, performed by the newly created enzyme systems. One of such highthroughput screening strategy for searching alkali lignindegrading microorganisms developed by Chong et al [40] is based on the ferricyanide-based assay involving the formation of Prussian blue. The use of this screening system made it possible to isolate from soil the strain Rhodococcus pyridinivorans CCZU-B16, capable of degradation 30.2% of 4 g/L alkali lignin under the nitrogen-limited condition at 30 °C for 72 h. In addition, a distinctive feature of this strain was the accumulation of lipids in the cells.…”

“…The use of this screening system made it possible to isolate from soil the strain Rhodococcus pyridinivorans CCZU-B16, capable of degradation 30.2% of 4 g/L alkali lignin under the nitrogen-limited condition at 30 °C for 72 h. In addition, a distinctive feature of this strain was the accumulation of lipids in the cells. Among the C16 and C18 fatty acid profiles, four major ones prevailed, including palmitic acid, palmitoleic acid, stearic acid and oleic acid [40].…”