Application of Thermomyces lanuginosus polygalacturonase produced in Komagataella phaffii in biomass hydrolysis and textile bioscouring.

In this work, the polygalacturonase (TL-PG1) from the thermophilic fungus Thermomyces lanuginosus was heterologously produced for the first time in the yeast Komagataella phaffii. The TL-PG1 was successfully expressed under the control of the AOX1 promoter and sequentially purified by His-tag affinity. The purified recombinant pectinase exhibited an activity of 462.6 U/mL toward polygalacturonic acid under optimal conditions (pH 6 and 55 ˚C) with a 2.83 mg/mL and 0.063 µmol/minute for Km and Vmax, respectively. When used as supplementation for biomass hydrolysis, TL-PG1 demonstrated synergy with the enzymatic cocktail Ctec3 to depolymerize orange citrus pulp, releasing 1.43 mg/mL of reducing sugar. In addition, TL-PG1 exhibited efficiency in fabric bioscouring, showing potential usage in the textile industry. Applying a protein dosage of 7 mg/mL, the time for the fabric to absorb water was 19.77 seconds (ten times faster than the control). Adding the surfactant Triton to the treatment allowed the reduction of the enzyme dosage by 50% and the water absorption time to 6.38 seconds. Altogether, this work describes a new versatile polygalacturonase from T. lanuginosus with the potential to be employed in the hydrolysis of lignocellulosic biomass and bioscouring.

Aqueous Extracts of Fermented Macrofungi Cultivated in Oilseed Cakes as a Carbon Source for Probiotic Bacteria and Potential Antibacterial Activity.

Plant biomass colonized by macrofungi can contain molecules with bioactive properties with applications to human/animal health. This work aimed to verify antibacterial activities from aqueous extracts from oil seed cakes of Jatropha curcas (JSC) and cottonseed (CSC), fermented by macrofungi for probiotic bacteria cultivation. Coriolopsis sp., Tyromyces sp., Panus lecomtei, and Pleurotus pulmonarius were cultivated in solid and submerged media. The aqueous extract of unfermented JSC was more efficient than glucose for the growth of all probiotic bacteria. Extracts from four macrofungi fermented in CSC favored Lactobacillus acidophilus growth. In solid fermentation, macrofungi extracts cultivated in JSC favored Bifidobacterium lactis growth. All fungi extracts showed more significant growth than carbohydrates among the four probiotic bacteria evaluated. Regarding antimicrobial activities, no fungal extract or bacterial supernatant showed a more significant inhibition halo for enteropathogenic bacteria than ampicillin (control). Extracts from P. lecomtei and Coriolopsis sp. in CSC showed inhibition halos for Salmonella enterica. Supernatants from L. acidophilus, B. lactis, and Lactobacillus rhamnosus resulted in more significant inhibition of Staphylococcus aureus than the control, which indicates possible antimicrobial activity. Unfermented JSC supernatant showed better results for bacterial growth, while supernatants and aqueous extracts from CSC fermentation can be used for probiotic bacteria culture.

Bioactives and Extracellular Enzymes Obtained from Fermented Macrofungi Cultivated in Cotton and Jatropha Seed Cakes.

This work focused on obtaining fermented oil cake (cotton or Jatropha) via macrofungi growth with potential characteristics for animal feed formulations, such as the presence of extracellular enzymes, bioactive (ergosterol and antioxidants), and detoxification of antinutritional compounds. The concentration of phorbol esters was reduced by four macrofungi in Jatropha seed cake (JSC) to non-toxic levels. At least two macrofungi efficiently degraded free gossypol in cottonseed cake (CSC). Fermentation with Coriolopsis sp. INPA1646 and Tyromyces sp. INPA1696 resulted in increased ergosterol concentrations, antioxidant activity reduction, and high activity of laccases and proteases. Bromatological analysis indicated high crude protein concentrations, with partial solubilization by fungal proteases. Fermented products from Coriolopsis sp. and Tyromyces sp. in JSC or CSC can be considered important biological inputs for monogastric and polygastric animal feed.

Actinomycetes inhibit filamentous fungi from the cuticle of Acromyrmex leafcutter ants.

Actinomycetes bacteria associated with leafcutter ants produce secondary metabolites with antimicrobial properties against Escovopsis, a fungus specialized in attacking the gardens of fungus-growing ants, which denies the ants their food source. Because previous studies have used fungi isolated from fungus gardens but not from ant integument, the aims of the present study were to isolate actinomycetes associated with the cuticle of the Acromyrmex spp. and to quantify their inhibition abilities against the filamentous fungal species carried by these ants. The results demonstrated that actinomycetes had varied strain-dependent effects on several filamentous fungal species in addition to antagonistic activity against Escovopsis. The strain isolated from Acromyrmex balzani was identified as a Streptomyces species, whereas the remaining isolates were identified as different strains belonging to the genus Pseudonocardia. These findings corroborate the hypothesis that actinomycetes do not act specifically against Escovopsis mycoparasites and may have the ability to inhibit other species of pathogenic fungi.