bacillamide-c and tryptamine

Tryptamine derivatives such as tryptamine and bacillamides were strong algicidal compounds promising in controlling harmful algae blooms, but their bioactivity and application researches were hindered by extremely low natural production rates. This study found an induced production of algicidal tryptamine derivatives by co-culture of marine Streptomyces with Bacillus mycoides, and optimised the culture method through changing important factors such as medium nutrition content, culture mode and pH value. The final established co-culture method used only 5 g yeast extracts and 5 g glycerol in 1 L 75% sea water, but got a yield of 14.9 mg/L N-acetyltryptamine, 2.8 mg/L N-propanoyltryptamine, 3.0 mg/L bacillamide A, 13.7 mg/L bacillamide B and 9.6 mg/L bacillamide C, which were all undetectable under normal culture conditions.

Topics: Bacillus; Coculture Techniques; Culture Media; Fermentation; Industrial Microbiology; Molecular Structure; Streptomyces; Thiazoles; Tryptamines

For biosynthesis of bacillamide C by Bacillus atrophaeus C89 associated with South China sea sponge Dysidea avara, it is hypothesized that decarboxylation from L-tryptophan to tryptamine could be performed before amidation by the downstream aromatic L-amino acid decarboxylase (AADC) to the non-ribosomal peptide synthetases (NRPS) gene cluster for biosynthesizing bacillamide C. The structural analysis of decarboxylases' known substrates in KEGG database and alignment analysis of amino acid sequence of AADC have suggested that L-tryptophan and L-phenylalanine are the potential substrates of AADC. The enzymatic kinetic experiment of the recombinant AADC proved that L-tryptophan is a more reactive substrate of AADC than L-phenylalanine. Meanwhile, the AADC-catalyzed conversion of L-tryptophan into tryptamine was confirmed by means of HPLC and LC/MS. Thus during bacillamide C biosynthesis, the decarboxylation of L-tryptophan to tryptamine is likely conducted first under AADC catalysis, followed by the amidation of tryptamine with the carboxylic product of NRPS gene cluster.

Topics: Amino Acid Sequence; Animals; Aromatic-L-Amino-Acid Decarboxylases; Bacillus; Decarboxylation; Dysidea; Molecular Sequence Data; Peptide Synthases; Phenylalanine; Sequence Alignment; Thiazoles; Tryptamines; Tryptophan