Production of 5‐aminolevulinic acid from hydrolysates of cassava residue and fish waste by engineered Bacillus cereusPT1

Abstract

The economical production of 5‐aminolevulinic acid (ALA) has recently received increasing attention for its extensive use in agriculture. In this study, a strain of Bacillus cereus PT1 could initially produce ALA at a titre of 251.72 mg/L by using a hydrolysate mixture of low‐cost cassava residue and fish waste. The integration of endogenous hemA encoding glutamyl‐tRNA reductase led to a 39.30% increase in ALA production. Moreover, improving cell permeability by deletion of the LytR‐CpsA‐Psr (LCP) family gene tagU led to a further increase of 59.73% in ALA production. Finally, the engineered strain B. cereus PT1‐ hemA ‐Δ tagU produced 2.62 g/L of ALA from the previously mentioned hydrolysate mixture in a 7‐L bioreactor. In a pot experiment, foliar spray of the ALA produced by B. cereus PT1‐ hemA ‐Δ tagU from the hydrolysates increased salt tolerance of cucumber by improving chlorophyll content and catalase activity, while decreasing malondialdehyde content. Overall, this study demonstrated an economic way to produce ALA using a microbial platform and evidenced the potential of ALA in agricultural application.

Efficient biosynthesis of 5-aminolevulinic acid from glutamate via whole-cell biocatalyst in immobilized engineered Escherichia coli

“…Recent studies have reported that the microbial production of ALA via the C5 pathway using glucose as the main substrate presented a conversion rate as low as 5.50–39.15%, 8 while it was also unfavorable for the purification of the product due to accumulating high byproduct. 33 Our present study described for the first time that engineered E. coli (BurAt-SalSL1 (T7)) achieved efficient ALA production using glutamate as substrate by whole-cell catalysis, providing an alternative strategy for ALA bioproduction.…”

“…The ALA concentration was analyzed as reported previously. 33 Briefly, the culture supernatants were reacted with acetylacetone (in sodium acetate buffer, pH 4.6, 0.2 M) at 100 °C for 15 min. Ehrlich's reagent 42 was added after cooling the samples to room temperature.…”

“…Cultivation of cucumber was performed as described previously. 33 Briefly, cucumber seeds were surface-sterilized and germinated in plastic containers containing nutrient soil and vermiculite. The seedlings were grown in a climate chamber.…”

Current trends in waste valorization

“…waste cooking oils) should be treated properly and used to produce value‐added products and realize circular bioeconomy and (iv) understanding the metabolic pathways and identifying the major enzymes and regulatory factors involved in the valorization of wastes requires an omics‐based approach (transcriptomics, proteomics and metabolomics). 5‐Aminolevulinic acid (ALA) has considerable agricultural applications as a plant growth regulator and as a photosynthesis enhancer (Luo et al, 2022 ). The hydrolysates of cassava residue (CR) and fish waste (FW) were utilized to manufacture ALA with Bacillus cereus PT1 (Luo et al, 2022 ), and the following findings were reported: (i) using CR hydrolysate (CRH) as a carbon source and tryptone as a nitrogen source, the ALA production was 140 mg/L, (ii) with glucose as a carbon source, FW hydrolysate (FWH) contributed to an ALA production of 195 mg/L and (iii) the ALA production was 2.6 g/L in a 7‐L fermenter employing CRH and FWH.…”

“…5‐Aminolevulinic acid (ALA) has considerable agricultural applications as a plant growth regulator and as a photosynthesis enhancer (Luo et al, 2022 ). The hydrolysates of cassava residue (CR) and fish waste (FW) were utilized to manufacture ALA with Bacillus cereus PT1 (Luo et al, 2022 ), and the following findings were reported: (i) using CR hydrolysate (CRH) as a carbon source and tryptone as a nitrogen source, the ALA production was 140 mg/L, (ii) with glucose as a carbon source, FW hydrolysate (FWH) contributed to an ALA production of 195 mg/L and (iii) the ALA production was 2.6 g/L in a 7‐L fermenter employing CRH and FWH. Zhang, Wang, Usman, et al ( 2022 ) investigated the possibility of producing biofuel from legume residues through the enzymatic saccharification of Caragana korshinskii Kom., silage treated with a rapid start‐up Pediococcus acidilactici strain and Acremonium cellulase.…”