1st International Conference on Chemo and BioInformatics, ICCBIKG 2021, (137-140)
AUTHOR(S) / AUTOR(I): Milanka Đ. Radulovic, Svetlana M. Mitrovski
E-ADRESS / E-ADRESA: mradulovic@np.ac.rs, smitrovski@gmail.com
DOI: 10.46793/ICCBI21.137R
ABSTRACT / SAŽETAK:
Peat is a natural substrate for growth of microorganisms because it is rich in compounds that microorganisms can use as sources of carbon, nitrogen and growth factors. Peat originating from Vlasina lake in Eastern Serbia is especially rich in organic matter. The content of humic substances (humic acid, fulvic acid and humine) is almost twice that found in other peat-rich regions of similar origin and geochemical age. Humic and fluvic acids are known to promote microbial growth. In this work, humic and fulvic acids were first extracted from Vlasina lake peat and then added to minimal medium (synthetic, low ionic strength medium). The humic substances were added separately and combined in a 1:1 ratio by mass to study their individual and combined effect on microbial growth of Escherichia coli ATCC 25922 (Gr–), Staphyloccocus aureus (Gr+) i Aureobasidium pullulans, strain CH-1.
The microbial growth was measured microspectrophotometrically over a 24-hour period and growth curves were obtained for a range of acid concentrations between 25 µg cm-3 and 100 µg cm-3. It was found that both humic and fulvic acids promote the growth of all three microorganisms by up to a maximum of 40%-80% the extent of which varied with the concentration of the acid and the identity of the microorganism. In general, humic acid was found to result in higher microbial growth (at highest concentrations, up to ~80% for all three microbial species).
KEY WORDS / KLJUČNE REČI:
peat, microbial growth, humic acids, fulvic acid
REFERENCES / LITERATURA:
- S.A. Visser, Effect of humic acids on numbers and activities of micro-organisms within physiological groups, Organic Geochemistry, 8 (1985) 81-85.