The biosorption of arsenic (As) with macroalgae has aroused much interest as a clean and low-cost technology. To evaluate arsenic biosorption by Chondracanthus chamissoi and Cladophora sp., approximately 5 kg of algae was collected from Huanchaco’s beach and Sausacocha lake (Huamachuco), La Libertad. As biosorption was carried out in four column systems, with 2 g of algae pellets each, circulating As solutions of 0.25 and 1.25 ppm, respectively, at 300 mL/min cm². As concentration was determined at 3 and 6 h of treatment by flame atomic absorption spectrophotometry. Data were analyzed using Student’s t-test with 95% confidence. At 6 h, Chondracanthus chamissoi presented an As biosorption of 95.76% in a 0.25 ppm mg/L solution and 85.33% in a 1.25 mg/L solution. Cladophora sp., at 6 h, presented an As biosorption of 95.76% in a 0.25 mg/L solution and 42.03% in a 1.25 mg/L solution. It was concluded that Chondracanthus chamissoi achieves higher percentages of biosorption than Cladophora sp. in solutions of 1.25 mg/L As (p < 0.05), and that there is no significant difference between the biosorption percentages of Chondracanthus chamissoi and Cladophora sp. in a 0.25 mg/L solution of As at 6 h of treatment (p > 0.05).

Bacterial cellulose (BC) is a pure, crystalline biopolymer with broad applications, though large-scale production remains limited by the high cost of culture media. This study evaluated the use of artichoke bract waste as an alternative substrate for BC production by Komagataeibacter rhaeticus QK23, focusing on culture optimization and physicochemical characterization of the resulting biopolymer. Infrared spectroscopy revealed functional groups characteristic of cellulose, hemicellulose, lignin, and inulin, along with structural sugars (glucose 24%, xylose 5.07%, arabinose 4.96%, galactose 8.81%, and mannose 1.75%). After hydrolysis with H₂SO₄, up to 11.81 g/L of reducing sugars were released and incorporated into Hestrin–Schramm medium lacking glucose. Using a central composite design, inoculum dose (10–20%) and incubation time (7–14 days) were optimized under static conditions at 30 °C. The highest yield (1.57 g/L) was obtained with 20% inoculum after 14 days. The product corresponded to type I cellulose with a crystallinity index of 81.87%, and AFM analysis revealed a surface roughness of 32.96 nm. The results demonstrate that artichoke hydrolysates are a viable and sustainable source for BC production, promoting agricultural waste valorization and cost reduction in industrial biotechnology.

Microorganisms’ degradation of agro-industrial waste produces bad odors and greenhouse gases that contribute to global warming. Consequently, eco-friendly, sustainable biotechnological alternatives to this waste are sought to provide additional value, which is why this study’s objective was to develop a method of producing unicellular proteins from artichoke and asparagus agro-industrial waste using Rhodotorula mucilaginosa as a producer organism. Agricultural soil was collected from the Universidad Nacional de Trujillo (Peru), and R. mucilaginosa was isolated and identified using biochemical tests. Proteins and carotenoids were produced from artichokes and asparagus residues using the R. mucilaginosa yeast. Four substrate concentrations (10, 20, 30, and 40%) and a pH range (5–8.1) were used. They were incubated at 30 °C for 72 h. The results showed that protein and carotenoid yield varied according to pH and substrate concentration. Artichoke residues reached a maximum protein yield of 25.98 mg/g and carotenoids of 159.26 μg/g at pH 5–6.6, respectively. Likewise, the asparagus residue showed a maximum protein yield of 20.22 mg/g and a carotenoid yield of 358.05 μg/g at a pH of 7.1 and 6.6, respectively. This study demonstrated the potential of artichoke and asparagus agro-industrial residues for the production of unicellular proteins and carotenoids using R. mucilaginosa. Further, it represents an appropriate alternative to properly managing agro-industrial waste, giving it an economic value.

Zea mays “maize” is one of the most important staple foods for both humans and animals, but it is highly susceptible to pathogens such as toxigenic Aspergillus flavus . Yeasts, however, have the potential to control the growth and activity of toxigenic fungi, representing a viable and economical alternative for biocontrol. This study is aimed at evaluating the efficiency of yeasts in controlling toxigenic A. flavus associated with maize grains. To achieve this, toxigenic A. flavus and yeast isolates were obtained and identified, then coinoculated in vitro to assess their effect on mycelial growth inhibition and total aflatoxin production through yeast‐derived volatile organic compounds (VOCs). We found that 147 of the isolated yeasts, when coinoculated with A. flavus , reduced mycelial growth up to 89%. VOCs from five yeast strains of the genera Saccharomyces and Meyerozyma inhibited colony growth up to 86% and induced changes at both the macro‐ and micromorphological levels in toxigenic A. flavus . Additionally, VOCs from four yeast strains reduced total aflatoxin levels up to 98%. In conclusion, one yeast strain, identified as Meyerozyma caribbica , effectively inhibited both mycelial growth and toxin production in toxigenic Aspergillus sp., demonstrating its potential as a biocontrol agent to reduce fungal contamination in maize grains.