Incubation of <italic>Aquilaria subintegra</italic> with Microbial Culture Supernatants Enhances Production of Volatile Compounds and Improves Quality of Agarwood Oil.

Monggoot, Sakon; Kulsing, Chadin; Wong, Yong Foo; Pripdeevech, Patcharee

Incubation with microbial culture supernatants improved essential oil yield from &lt;italic&gt;Aquilaria subintegra&lt;/italic&gt; woodchips. The harvested woodchips were incubated with de man, rogosa and sharpe (MRS) agar, yeast mold (YM) agar medium and six different microbial culture supernatants obtained from &lt;italic&gt;Lactobacillus bulgaricus&lt;/italic&gt;, &lt;italic&gt;L. acidophilus&lt;/italic&gt;, &lt;italic&gt;Streptococcus thermophilus&lt;/italic&gt;, &lt;italic&gt;Lactococcus lactis&lt;/italic&gt;, &lt;italic&gt;Saccharomyces carlsbergensis&lt;/italic&gt; and &lt;italic&gt;S. cerevisiae&lt;/italic&gt; prior to hydrodistillation. Incubation with lactic acid bacteria supernatants provided higher yield of agarwood oil (0.45% w/w) than that obtained from yeast (0.25% w/w), agar media (0.23% w/w) and water (0.22% w/w). The composition of agarwood oil from all media and microbial supernatant incubations was investigated by using gas chromatography-mass spectrometry. Overall, three major volatile profiles were obtained, which corresponded to water soaking (control), as well as, both YM and MRS media, lactic acid bacteria, and yeast supernatant incubations. Sesquiterpenes and their oxygenated derivatives were key components of agarwood oil. Fifty-two volatile components were tentatively identified in all samples. Beta-agarofuran, α-eudesmol, karanone, α-agarofuran and agarospirol were major components present in most of the incubated samples, while &lt;italic&gt;S. cerevisiae&lt;/italic&gt;-incubated &lt;italic&gt;A. subintegra&lt;/italic&gt; provided higher amount of phenyl acetaldehyde. Microbial culture supernatant incubation numerically provided the highest yield of agarwood oil compared to water soaking traditional method, possibly resulting from activity of extracellular enzymes produced by the microbes. Incubation of agarwood with lactic acid bacteria supernatant significantly enhanced oil yields without changing volatile profile/composition of agarwood essential oil, thus this is a promising method for future use.

VOLATILE organic compounds; AQUILARIA; MICROBIAL cultures; ESSENTIAL oils; PLANT-bacteria relationships

Indian Journal of Microbiology, 2018, Vol 58, Issue 2, p201

0046-8991

Academic Journal

10.1007/s12088-018-0717-1