Acetylacetoin synthase as a marker enzyme for detecting the 2,3-butanediol cycle

A Summary of Producing Acetoin by Biological Method

“…In Serratia marcescens, the metabolic regulation mechanism of branched-chain amino acids and the synthesis of acetoin are shown in Figure 2 Although there are differences in the structure and properties of some enzymes related to the metabolism of acetoin in different microorganisms, different scholars have different opinions, but so far, there are a large number of studies in biochemical and molecular organisms on the synthesis of acetoin pathway by bacteria. it have been have confirmed that the metabolic pathway of acetoin mainly involves the glycolysis (EMP) pathway of glucose metabolism (glucose to pyruvate) and the conversion of pyruvate to acetoin, as shown in Figure 3 [31,[36][37][38][70][71][72][73][74]. There are two main ways to synthesize acetoin in microorganisms: Two molecules of pyruvic acid synthesize a molecule of α-acetolactate under the action of α-acetolactate synthetase, alpha-acetolactate is naturally oxidatively decarboxylated under acidic conditions to form 2,3-butanedione, 2,3-butanedione is reduced to produce acetoin by the action of butanedione reductase or 2,3-butanediol dehydrogenase, Another way, Two molecules of pyruvic acid synthesize a molecule of α-acetolactate under the action of α-acetolactate synthase, the α-acetolactate is converted to acetoin by the action of α-acetolactate decarboxylase.…”

“…With the development of enzyme engineering technology, there have been many successful examples of enzyme conversion technology replacing traditional chemical processes. The key to this process is to obtain a large number of specific enzymes [19][20][21][22][34][35][36][37][38]. In 1992, Hummel et al [9] in the United States applied butanone reductase (diacetyl reductase) in Lactobacillus or Yeast cells as a biocatalyst to catalyze the reduction of butanone to acetoin.…”

“…[27] Compared with chemical synthesis and enzymatic conversion, the production of acetoin by microbial fermentation has the advantages of simple process, mild conditions, environmental friendliness, abundant raw material source and renewable, and the product can be regarded as pure natural and high security, which is the most economically viable production method for acetoin. With the deepening of research on the production of acetoin by fermentation, advanced biotechnology and traditional breeding techniques are combined to breed and construct high-yield, high-performance acetoin-producing strains, while focusing on the supporting research on the upstream and downstream technologies for the production of acetoin by fermentation, it is the key to realizing the producing acetoin by bio-fermentation as soon as possible [36][37][38][39][50][51][52][53][54][55].…”

“…The more accepted meaning is to resist environmental acidification, participate in the regulation of NAD/NADH ratios, and act as a storage carbon source. Recognizing that bacteria can use acetoin as a carbon source and energy source for growth for more than 80 years [41,60,61,38,[82][83]. The acetoin combination metabolic pathway involves many enzymes such as α-acetolactate synthase and α-acetolactate decarboxylase.…”

“…Ali et al [47] also confirmed that the cumulative acetoin will not continue to be consumed when the strain acoA gene is deleted. A growing number of studies have shown that 3-hydroxybutanone is primarily degraded by the direct oxidative cleavage pathway of the acetoin dehydrogenase system (AoDH ES) in bacteria [38,83,86,95]. In summary, the relevant pathways for bacterial metabolism of acetoin are shown in Figure 7 [92][93][94][95][96][97][98].…”