Unlocking the Potential of Substrate Quality for the Enhanced Antibacterial Activityof Black SoldierFly against Pathogens

Abstract

Globally,antibiotics are facing fierce resistance from multidrug-resistant bacterials trains.There is an urgentneedfor eco friendly alternatives.Though insects are important targets for antimicrobial peptides,it has received limited research attention.This study investigated the impact of waste substrates on the production of antibacterial agents in black soldierfly (HermetiaillucensL.) larvae(HIL)andtheirimplicationsin the suppressionofpathogens[Bacillussubtilis(ATCC6051),Staphylococcusaureus(ATCC25923),Pseudomonasaeruginosa(ATCC27853),andEscherichiacoli(ATCC25922)].The20%aceticacid(AcOH)extractfrommarketwastehadthe highestantibacterialactivitywithan inhibitionzoneof 17.00mm,followedby potatowaste(15.02mm)againstS. aureus.HexaneextractfromHILraisedon marketwastealsoshoweda significantinhibitoryzone(13.06mm)againstB. subtilis..Minimuminhibitoryconcentration(MIC)valuesrecordedwere25 mg/mLagainstall test pathogens.Thefastesttime-killof 20%AcOHextractwas4 h againstB.subtilis,E. coli,,andP. aeruginosa.Lauricacidwasalsoidentifiedas the dominantcomponentof the varioushexaneextractswithconcentrationsof602.76and318.17μg/gin HILrearedon potatoandmarketwaste,respectively.Energyfromthe marketwastesubstratecorrelatedsignificantly(r= 0.97)withantibacterialactivities.Thisstudyhighlightsthe key roleof substratequalityandextractionmethodsforenhancingthe productionof antibacterialagentsin HIL,thusprovidingnewinsightsintothe developmentof potentialdrugstoovercomethe alarmingconcernsof antimicrobialresistance.