d-Amino Acids and Lactic Acid Bacteria.

Area of Science:

• Biochemistry
• Microbiology
• Food Science

Background:

• Proteins primarily use l-amino acids, with d-amino acids historically overlooked.
• Recent advances reveal diverse roles for d-amino acids in organisms, from neurotransmission to bacterial processes.
• Lactic acid bacteria are known producers of various d-amino acids.

Purpose of the Study:

• To review the significance of d-amino acids, particularly those produced by lactic acid bacteria.
• To highlight the functional and sensory contributions of d-amino acids in fermented foods.
• To discuss the search for novel d-amino acid-metabolizing enzymes in lactic acid bacteria.

Main Methods:

• Literature review of d-amino acid research.
• Analysis of d-amino acid roles in human health and microbial metabolism.
• Examination of d-amino acid production by lactic acid bacteria.

Main Results:

• D-amino acids have crucial functions, including neurotransmission (d-serine) and hormone-like activity (d-aspartate).
• Certain d-amino acids act as biofilm disassembly factors in bacteria.
• Many d-amino acids produced by lactic acid bacteria contribute to sweet taste and beneficial properties in fermented foods.

Conclusions:

• D-amino acids are important for the sensory and functional qualities of lactic-acid-fermented foods.
• The unique d-amino acid-metabolizing enzymes in lactic acid bacteria warrant further investigation.
• Understanding d-amino acid roles enhances appreciation for fermented food products and their health implications.