Application potential of modified waste-lignin as microbial immobilization carriers for improve soil fertility

Abstract

The immobilized microorganism technology is used to load the functional microorganism on a suitable carrier to maintain its biological activity, resist the impact of adverse environment. In this study, chemical modification of lignin side chain phenolic hydroxyl groups was carried out to increase the content of amide functional groups and enhance their adsorption and fixation effects on microorganisms due to the numerous active sites in the structure of discarded lignin, and studied its impact on microbial activity and crop growth. The results show that the modified lignin could be effectively combined with functional microorganisms, and the proposed bio-composite material was an effective method for cell protection. In addition, it was shown that functional microorganisms maintained high biological activity by immobilization of modified lignin, which was 34.3–41.0% higher than that of CK. Moreover, the technology could increase the total nitrogen content and available phosphorus content in soil by 70.8% and 64.4%, respectively, compared with CK. Therefore, it could increase eventually wheat growth indices and biomass. The completed research opens new perspectives for the effective immobilization of microorganisms and utilization of wasted lignin of significant economic importance.