Acid mine drainages (AMDs) enriched with toxic metals pose a significant environmental risk. Microbial bioremediation offers a sustainable and cost-effective approach for metal removal from AMD. In this study, a wild yeast isolated from the Kavart abandoned mine, identified as Rhodotorula sp., was evaluated for its copper (Cu²⁺) and zinc (Zn²⁺) biosorption ability. Biosorption was strongly pH-dependent. Cu²⁺ and Zn²⁺ removal was most efficient (48.1% or 10.07 mg/g and 35.7% or 6.07 mg/g, respectively) at pH 6. Increasing the biomass to 3 g/L at the same pH enhanced Cu²⁺ removal to 71.5% (26 mg/g). Biosorption kinetic analysis showed an excellent fit to the pseudo-second-order model (R² > 0.99), indicating that the mechanism is chemisorption-dominated. Equilibrium data followed the Langmuir isotherm (R² = 0.93), consistent with monolayer adsorption on homogeneous binding sites. SEM-EDS analysis confirmed Cu²⁺ association with the yeast surface, supporting the ICP-OES results. The results demonstrate the isolate as a promising biosorbent, particularly for Cu²⁺, and highlight its potential application in the remediation of AMD-contaminated waters.

Chloride ions can enhance the bioleaching of copper minerals, yet most biomining microorganisms are highly sensitive to chloride and cannot survive or colonize mineral surfaces in saline environments. Chloride tolerance varies among acidophilic iron-oxidizing bacteria, but the concentrations at which they remain active are generally too low to permit the industrial use of seawater. Therefore, identifying highly chloride-tolerant leaching microorganisms and studying their bioleaching potential in chloride-containing systems is of utmost importance. This study investigated chloride tolerance and adaptability of bacteria from different genera, with a focus on Sulfobacillus thermosulfidooxidans subsp. asporogenes 41, a moderately thermophilic strain that can oxidize both Fe (II) and reduced inorganic sulfur compounds (RISCs). This dual activity makes it advantageous for bioleaching by facilitating sulfur removal, generating acidity, and preventing mineral passivation. Comparative experiments on the bioleaching of pyrite and chalcopyrite demonstrated that adaptation to 0.3 M NaCl enhanced the chloride tolerance of S. thermosulfidooxidans subsp. asporogenes 41. The adapted strain exhibited significantly improved copper extraction under saline conditions compared with the native culture. Maximum copper recovery was achieved at 0.4 M NaCl, highlighting the potential of chloride-adapted moderate thermophiles for biomining applications in saline environments. In contrast the minimal inhibitory concentration for Acidithiobacillud ferrooxidans Dr was 0.005 M (causing 41.2% inhibition), while Leptospirillum ferriphilum CC was unaffected by lower concentrations (0.01–0.02 M) and only showed severe inhibition (86.5%) at 0.1 M NaCl, defining its minimal inhibitory concentration (MIC) at 0.05 M.

The concept of sustainable agricultural development is aimed at reducing the use of chemical pest control agents. Since the use of chemical pesticides poses a significant environmental threat, one of the possible solutions to overcome this problem is the study of biological approaches, in particular, the use of entomopathogenic microorganisms as biological pest control agents. Insecticidal activity of over 220 strains of Bacillus thuringiensis (Bt) and Lysinibacillus sphaericus from the collection of the Laboratory of Spore-Forming Microorganisms of the Microbial Depository Center of the Scientific and Production Center “Armbiotechnology” and 15 strains isolated from samples of dead insects (imago) of representatives of various genera of the Coleoptera order was studied. The pathogenic effect of the strains was assessed in relation to the insect species Tenebrio molitor, Zophobas morio, Leptinotarsa decemlineata Say and Pieris brassicae, belonging to the Coleoptera and Lepidoptera orders. Among the test objects, the representative of Lepidoptera Pieris brassicae demonstrated the highest degree of sensitivity to B. thuringiensis strains up to 100%, with some Bt strains causing 60–100% mortality of Tenebrio molitor and Zophobas morio larvae of different ages. The larvae of the beetle Leptinotarsa decemlineata Say were also partially susceptible, presenting mortality levels of between 31 and 60%. The article is devoted to the study of Bt bacterial strains that have pronounced insecticidal activity against insect larvae of the orders Coleoptera and Lepidoptera.

Acid mine drainages (AMDs) contaminated with heavy metals pose a significant environmental challenge. Today, various strategies are employed to combat heavy metal pollution, including using microorganisms for bioremediation. Among these strategies, biosorption by microorganisms, particularly yeasts, has emerged as a promising approach for removing heavy metals from the environment. This study aimed to isolate and characterize a yeast strain collected from Kavart tailing site, with potential biosorption capacity, focusing on copper (Cu²⁺) and zinc (Zn²⁺) at varying pH levels (2, 4, and 6). The biosorption of Cu²⁺ showed the highest removal efficiency at pH 6, with approximately 71.5% metal removal at 3 g/L biomass concentration. The Zn²⁺ biosorption was less efficient, with a maximum removal of 29.3% at pH 6. However, further research will focus on optimizing biosorption conditions and understanding the mechanisms of metal binding to yeast cells.