thidarat boonlerd

thidarat boonlerd

orcid

Research Focus & Metrics

Academic Career Length

1Year (2026-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

View All Publications
28 September 2026 in Preprints.org
Verified
Preprint
Open access
PDF file
TMThanakorn Moktip
Thanakorn Moktip
TBthidarat boonlerd
thidarat boonlerd
LSLakha Salaipeth
Lakha Salaipeth
SASaengchai Akeprathumchai
Saengchai Akeprathumchai
Ken-lin ChangKen-lin Chang
Ken-lin Chang
Paripok PhitsuwanParipok Phitsuwan
Paripok Phitsuwan
Efficient microbial conversion of chicken-feather keratin into value-added products offers a sustainable approach to waste valorization. Bacillus sp. strain 46-2, isolated from a hot spring in Thailand, produced extracellular caseinolytic and keratinolytic enzymes capable of degrading keratinous and non-keratinous protein substrates. The crude enzyme preparation remained active over a broad pH range of 6.0–11.0 and exhibited maximal caseinolytic and keratinolytic activities at 50 °C. Certain metal ions, including Cu²⁺, Ni²⁺, and Zn²⁺, reduced one or both activities, while SDS, Tween 20, and Triton X-100 also caused varying degrees of inhibition. The addition of reducing agents enhanced feather degradation, with β-mercaptoethanol and Na₂SO₃ increasing chicken-feather mass loss to 73% and 47%, respectively, after 24 h. SDS–PAGE and zymographic analyses revealed multiple proteolytic and keratinolytic activity bands, while inhibition by PMSF and EDTA suggested contributions from serine proteases and metal-dependent proteases. Peptide-rich fractions obtained from the culture supernatant exhibited ABTS radical-scavenging activity, with IC₅₀ values of 506.25, 449.70, and 190.10 µg mL⁻¹ for the >10 kDa, 3–10 kDa, and <3 kDa fractions, respectively. Thin-layer chromatography detected spots corresponding to leucine, valine, glutamic acid, serine, and glycine in the hydrolysate. Overall, Bacillus sp. strain 46-2 is a promising source of alkaline-active and moderately thermostable proteolytic and keratinolytic enzymes for the bioconversion of keratin-rich waste into amino acids and antioxidant peptide-rich fractions with potential value for cosmetic and healthcare-related applications.