This paper provides a review of the latest research findings on the applications of microbial chitinases to biological control. Microorganisms producing these enzymes can inhibit the growth of many fungal diseases that pose a serious threat to global crop production. Currently, efforts are being made to discover producers of chitinolytic enzymes. The potential exists that natural biofungicides will replace chemical fungicides or will be used to supplement currently used fungicides, which would reduce the negative impact of chemicals on the environment and support the sustainable development of agriculture and forestry.

Biodegradable films based on starch modified with ascorbic acid or caffeine and dialdehyde starch (DS) were evaluated towards their applications in the food packaging industry. The morphology of the films surface was observed with SEM and AFM. The chemical structure was examined with ATR-FTIR spectroscopy and X-ray diffraction. The mechanical, thermal and barrier properties of the films were examined. The cross-linking and hydrophobic effect of dialdehyde starch on starch-based films was proven. Vitamin C addition prompts the crystalline structure formation and improves the hydrophilicity and antioxidant activity of the starch blends. Caffeine addition results in higher starch film hydrophobicity, whereas caffeine combined with DS reduces crystalline order in starch. Both caffeine and ascorbic acid incorporation influence the film stiffness, and dialdehyde starch causes an increase in brittleness. The high susceptibility to biodegradation and good antioxidant activity confirms the potential application of examined systems in the packaging industry.

This paper presents the results of the study on the production of protease by Bacillus luteus H11 isolated from an alkaline soda lime. B. luteus H11 was identified as an alkalohalophilic bacterium, and its extracellular serine endoprotease also showed an extreme alkali- and halotolerance. It was remarkably stable in the presence of NaCl up to 5 M. The enzyme was active in a broad range of pH values and temperatures, with an optimum pH of 10.5 and a temperature of 45 °C. It had a molecular mass of about 37 kDa and showed activity against azocasein and a synthetic substrate for the subtilisin-like protease, N-succinyl-l-phenylalanine-p-nitroanilide. The halo-alkaline protease produced by B. luteus H11 seems to be significant from an industrial perspective because of its tolerance towards high salinity and alkalinity as well as its stability against some organic solvents, surfactants and oxidants. These properties make the protease suitable for applications in food, detergent and pharmaceutical industries, and also in environmental bioremediation.

Inorganic aluminum or iron salts supported with synthetic polymers are commonly used to eradicate colloidal particles from water in coagulation and flocculation processes. Nevertheless, these agents have several disadvantages, such as large volumes of sludge produced or environmental toxicity. Recently biodegradable polymers have been suggested as eco-friendly flocculants for water treatment. This study aimed to investigate the possibilities of using starch and chitosan and their oxidized derivatives as flocculants for filter backwash water treatment. Dialdehyde starch (DST) and dialdehyde chitosan (DCT) were synthesized by periodate oxidization of natural starch from corn and low molecular weight chitosan. The obtained materials have been characterized with scanning electron microscopy (SEM), ATR-FTIR spectroscopy, and thermogravimetric analysis (TGA). Furthermore, we studied the flocculation properties of polysaccharide flocculants in a series of jar tests. The effectiveness of chitosan and starched-based flocculants was compared to synthetic polymers commonly used to treat iron ions-rich filter backwash water. The environmental aspects of these chemicals, particularly the biodegradability of post-flocculation residues, were also addressed. It was found that oxidized starch and chitosan derivatives can be used as ecological flocculating materials to treat potable water or sludge.

The present research was aimed at assessing the quality of air and soil on the premises and in the vicinity of the municipal landfill sites in Toruń with regard to the presence of pathogenic bacteria, potentially dangerous to humans. Air samples (the impaction method using a MAS-100 impactor) and soil samples were collected from seven sampling sites including the operating and closed landfill cells, sampling sites located near leachate ponds, and sampling sites located outside the above premises. The research also involved assessing microbial air contamination in three indoor spaces on the premises of the landfill sites. Microbial tests involved the determination of the number of culturable mesophilic, mannitol-positive, and α- and β-hemolytic bacteria in the air, determination of the number of coliform bacteria, spore-forming Clostridium perfringens in soil, and the presence of Salmonella in soil. The results indicate that bioaerosol emitted by this municipal facility is the source of hemolytic bacteria (≤300 CFU m⁻³ of air), as well as of pathogenic bacteria (Pseudomonas aeruginosa and Bacillus subtilis). The highest risk of exposure to biological agents was determined in the sorting facility. Over sixty percent of air samples in this sampling site presented high pollution degree with mesophilic bacteria (500–2000 CFU m⁻³ of air) and over one fourth of air samples presented very high pollution degree (>2000 CFU m⁻³ of air). Indoor air in other rooms was considered highly/moderately contaminated (100–2000 CFU m⁻³ of air). The highest risk related to the presence of Salmonella, Clostridium perfringens, and coliform bacteria in soil was determined at the operating landfill cell and near the leachate pond of the closed landfill cell. At the operating landfill cell the total coli ranged from 4–1226 MPN g⁻¹ of dry mass of soil and Clostridium perfringens ranged from <LOD-1604 CFU g⁻¹ of dry mass of soil. The results question the strategy of municipal landfill sites in densely populated areas, and emphasize the need for regular monitoring of microbiological tests in their vicinity as well as for control strategies in order to protect workers at landfill sites. The results of the study should be used for future decisions on the location of municipal landfill sites and suggest the need for better environmental control technologies in the sites that are already functioning.

The present study was aimed at investigating bactericidal properties of polylactide (PLA) films containing three different polyhexamethylene guanidine hydrochloride (PHMG) derivatives and effect of the derivatives on extracellular hydrolytic enzymes and intracellular dehydrogenases. All PHMG derivatives had a slightly stronger bactericidal effect on Staphylococcus aureus than on E. coli but only PHMG granular polyethylene wax (at the concentration of at least 0.6 %) has a bactericidal effect. PHMG derivatives introduced into PLA affected the activity of microbial hydrolases to a small extent. This means that the introduction of PHMG derivatives into PLA will not reduce its enzymatic biodegradation significantly. On the other hand, PHMG derivatives introduced into PLA strongly affected dehydrogenases activity in S. aureus than in E. coli.