From tilapia (Oreochromis niloticus) farming, the by-products have been identified as a source of collagen that could be used for the development of dermocosmetics or pharmaceutical products. However, the characteristics of collagen related to a specific strain or culture must be well defined prior to its application. Collagen was extracted from the skin of three strains of tilapia: red YY males (YY: two Y-type sex chromosomes), XX gray females, and the F1: offspring of crossing red YY males with XX gray females; at different ages in the adult phase, using acetic acid and pepsin enzyme. The characteristics of acid-soluble collagen (ASC) and pepsin-soluble collagen (PSC) were shown by SDS-PAGE band profiles to be similar to bovine collagen type I (SIGMA), the PSC of gray tilapia being more fragile to temperature changes, consistent with the results of fractional viscosity. The characteristics of the F1 progeny were prioritized for being a commercially productive and sustainable source for the extraction of collagen, and the ASC form, being the one with the greatest stability and advantage over PSC, of importance to our investigations, leads to a controlled digestion as in the case of peptide induction, and also in the development of natural products in the pharmaceutical and/or dermocosmetic industry. Evaluations of the triple helix structure by FT-IR, X-ray diffraction and UV–visible spectroscopy give similar results between the strains: red, gray, and F1, and between ages in the adult form F1 (15, 24, and 36 months of age). Consequently, the skin of tilapia in adult form is recommended sustainably for up to 24 months of age where the collagen is obtained with the use of acetic acid without enzymatic treatment.

Bacterial cellulose is a biomaterial known for its physical and mechanical properties, including its high mechanical strength, water retention capacity, and biocompatibility. Its production from various carbohydrates has been widely studied, aiming to find more efficient and cost-effective culture media. This study investigated the production of bacterial cellulose from agroindustrial asparagus peel waste by Komagataeibacter rhaeticus QK23. A strain of QK23 was isolated and cultivated from a kombucha tea, identified based on morphological and molecular characteristics using the 16S rRNA gene. The waste was hydrolyzed and converted into fermentable sugars. Using the response surface methodology, the inoculum dose (1–20%) and incubation time (3–25 days) were evaluated concerning bacterial cellulose yield. The results demonstrated that with an optimal inoculum dose of 10.5% and an incubation time of 25 days, a production of 2.57 g/L was achieved. It was characterized as similar to type I cellulose, exhibiting a high degree of crystallinity (81.89%) and suitable morphological properties, evidenced by a fiber size of 178 nm and a surface roughness of 27.05 nm. Converting asparagus waste into bacterial cellulose is a sustainable and effective strategy that promotes the development of advanced biomaterials in biotechnology research.

The effluents generated in the paper industry, such as black liquor, have a high content of lignin and other toxic components; however, they represent a source of lignin-degrading bacteria with biotechnological potential. Therefore, the present study aimed to isolate and identify lignin-degrading bacteria species in paper mill sludge. A primary isolation was carried out from samples of sludge present in environments around a paper company located in the province of Ascope (Peru). Bacteria selection was made by the degradation of Lignin Kraft as the only carbon source in a solid medium. Finally, the laccase activity (Um-L⁻¹) of each selected bacteria was determined by oxidation of 2,2′-azinobis-(3-etilbencenotiazolina-6-sulfonate) (ABTS). Bacterial species with laccase activity were identified by molecular biology techniques. Seven species of bacteria with laccase activity and the ability to degrade lignin were identified. The bacteria Agrobacterium tumefasciens (2), Klebsiella grimontii (1), and Beijeinckia fluminensis (1) were reported for first time. K. grimowntii and B. fluminensis presented the highest laccase activity, with values of 0.319 ± 0.005 UmL⁻¹ and 0.329 ± 0.004 UmL⁻¹, respectively. In conclusion, paper mill sludge may represent a source of lignin-degrading bacteria with laccase activity, and they could have potential biotechnological applications.

The carotenoids have vast medical, industrial, dietary, and pharmaceutical importance due to their provitamin A precursor, immunomodulator, antioxidant and photoprotective activity. The purpose of the research was to optimize the production of carotenoids using Rhodotorula mucilaginosa from artichoke agroindustrial waste as a low-cost substrate. The artichokes bracts waste was bleached by sodium hypochlorite (NaClO 2%) and was characterized through whiteness index and FTIR. The bleached artichoke waste (BABW) used in the fermentation went through acid hydrolysis, applying 8% of the bleached artichokes residue and sulfuric acid (2.5%) for 1 h at 90°C, obtaining a greater reduced sugars content at 3.1 g/L. Rhodotorula mucilaginosa was isolated and molecularly identified. The production of carotenoids from a culture media based on hydrolyzed BABW, peptone (0.5%), yeast extract (0.1%) and sodium chloride (0.5%) was evaluated at different conditions of pH (5–8) and agitation speed (80–160 rpm) applying the surface response methodology by a rotational central compound design. The best carotenoids performance obtained had 2968.95 µg/L VVC and 1228.53 µg/g TFC at pH 5, 120 rpm and 30°C for 72 h. The chemical characterization of the extracted carotenoids was confirmed by UV-VIS and Raman spectroscopy methods. The results suggest that Rhodotorula mucilaginosa is capable of producing carotenoids from artichoke waste fermentation, providing a low-cost and sustainable alternative route for use in the global market.

Pollution from crude oil and its derivatives poses a serious threat to human health and ecosystems, with accidental spills causing substantial damage. Biodegradation, using microorganisms to break down these contaminants, presents a promising and cost-effective solution. Exploring and utilizing new bacterial strains from underexplored habitats could improve remediation efforts at contaminated sites. This study aimed to evaluate the hydrocarbon biodegradation capacity of bacteria isolated from agricultural soils in Huamachuco, Peru. Soil samples from Oca crops were collected and bacteria were isolated. Biodegradation assays were conducted using diesel as the sole carbon source in the Bushnell Haas Mineral medium. Molecular characterization of the 16S rRNA gene identified four strains. Diesel biodegradation assays at 1% concentration were performed under agitation conditions at 150 rpm and 30 °C, and monitored on day 10 by measuring cellular biomass (OD₆₀₀), with hydrocarbons analyzed by gas chromatography. The results showed Pseudomonas protegens (PROM2) achieved the highest efficiency in removing total hydrocarbons (91.5 ± 0.7%). Additionally, Pseudomonas citri PROM3 and Acinetobacter guillouiae ClyRoM5 also demonstrated high capacity in removing several individual hydrocarbons. Indigenous bacteria from uncontaminated agricultural soils present a high potential for hydrocarbon bioremediation, offering an ecological and effective solution for soil decontamination.