Biotechnology Reports (Mar 2024)

The potential of Hungarian bauxite residue isolates for biotechnological applications

  • Viktória Feigl,
  • Anna Medgyes-Horváth,
  • András Kari,
  • Ádám Török,
  • Nelli Bombolya,
  • Zsófia Berkl,
  • Éva Farkas,
  • Ildikó Fekete-Kertész

Journal volume & issue
Vol. 41
p. e00825

Abstract

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Bauxite residue (red mud) is considered an extremely alkaline and salty environment for the biota. We present the first attempt to isolate, identify and characterise microbes from Hungarian bauxite residues. Four identified bacterial strains belonged to the Bacilli class, one each to the Actinomycetia, Gammaproteobacteria, and Betaproteobacteria classes, and two to the Alphaproteobacteria class. All three identified fungi strains belonged to the Ascomycota division. Most strains tolerated pH 8–10 and salt content at 5–7% NaCl concentration. Alkalihalobacillus pseudofirmus BRHUB7 and Robertmurraya beringensis BRHUB9 can be considered halophilic and alkalitolerant. Priestia aryabhattai BRHUB2, Penicillium chrysogenum BRHUF1 and Aspergillus sp. BRHUF2 are halo- and alkalitolerant strains. Most strains produced siderophores and extracellular polymeric substances, could mobilise phosphorous, and were cellulose degraders. These strains and their enzymes are possible candidates for biotechnological applications in processes requiring extreme conditions, e.g. bioleaching of critical raw materials and rehabilitation of alkaline waste deposits.

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