# Genome-Guided Identification of an OTA-Degrading Amidohydrolase AMH2102 from Acinetobacter kookii AK4 with Enhanced Soluble Expression in Escherichia coli

## TL;DR

Researchers identified a highly efficient OTA-degrading enzyme from Acinetobacter kookii and improved its expression in E. coli for rapid toxin removal.

## Contribution

A novel OTA-degrading amidohydrolase AMH2102 was identified and its soluble expression was significantly enhanced in E. coli.

## Key findings

- Acinetobacter kookii AK4 degraded 95.44% of OTA within 6 hours.
- Codon optimization and SUMO tagging increased AMH2102 soluble expression 14.81-fold.
- AMH2102 achieved 100% OTA degradation within 3 minutes.

## Abstract

Ochratoxin A (OTA) is a globally distributed mycotoxin that poses serious threats to food safety and human health due to its nephrotoxic, hepatotoxic, and carcinogenic properties. Previous enzymatic detoxification strategies for OTA have been constrained by low degradation efficiency or poor soluble expression of highly active enzymes. In this study, a bacterial strain with strong OTA-degrading activity was isolated and identified as Acinetobacter kookii AK4, which degraded 95.44% of 1 μg/mL OTA within 6 h. The predominant OTA-degrading activity was derived from intracellular enzymes. Through genome mining and experimental validation, gene2102 was identified as encoding an amidohydrolase. The enzyme was designated AMH2102 and was heterologously expressed in Escherichia coli. Codon optimization combined with fusion of an N-terminal SUMO tag increased the soluble expression of AMH2102 by 14.81-fold, enabling complete (100%) OTA degradation within 3 min. Overall, this study achieved the identification of an efficient OTA-degrading strain and enzyme and explored strategies for improving enzyme expression, yielding effective outcomes that provide useful references for future studies on strain mining and enzyme engineering.