The aim of this study was to select keratin-degrading bacteria from JSC “Biocentras” collection and poultry processing plant wastewater, and to study their ability to degrade chicken feathers. Isolated from poultry processing plant wastewater bacteria was grown in basal media with feathers meal and showed high keratinolytic activity and protein content throughout the cultivation time. Bacterial strains B. licheniformis 511, B. subtilis I1, B. subtilis 717, and B. subtilis 103 suggested strongly of bacteria that produces keratinolytic activity in the cell free culture supernatants. The obtained results showed that maximum activity of keratinase is a function of cultivation time by the bacteria tested. B. subtilis 103 reached to its maximum level of keratinase production (152 U/mL) after 24 hrs, when over bacteria (148-242 U/mL) after 48 hrs. The good ability of selected bacteria to degrade feathers was detected. The best biodegradation of feathers was obtained using B. subtilis I-1. Over bacillus good degraded feathers as well.

The aim of this study was to identify and optimize significant technological parameters influencing keratinolytic enzyme production by A. fradiae 119 and to study its ability to degrade keratin. In the present work chicken feathers meal (CFM) was found to be an excellent substrate for keratinase induction by A. fradiae 119. The strain produced 164 KU/mL keratinolytic activity in basal medium containing 7.5 g/L CFM as the sole source of carbon and nitrogen. Increased keratinolytic activity was achieved in media with ammonium sulfate as nitrogen source, the application of additional nitrogen sources to media containing CFM slightly decreased keratinase synthesis. Optimal parameters of the cultivation process were determined: pH of cultivation medium – 7.2, temperature – 34 ºC and inoculum’s size – 8 %, using the response surface methodology. The yield of keratinase activity was increased by 46 % (267 KU/mL) after optimization of the cultivation process. The good ability of cultural liquid to degrade feathers and wool was detected.

The complex, effective and innovative cleaning technology for lipid-rich wastewater and pipelines contaminated by lipids, was developed. For this purpose, laboratory experiments were performed to verify the efficiency of bacterial preparation (Enterobacter aerogenes E13, Arthrobacter sp. N3 and Bacillus coagulans S1) to degrade the grease in water and in drainpipes. The results showed that selected microorganisms intensively degrade grease to light odourless precipitate, water and CO2, thus could be applied in industry. For optimization of technological cleaning processes, the response surface methodology was used. The optimal parameters for biological model wastewater treatment were determined: concentration of grease − 4.5–6.0 g/l, amount of bacterial preparation −5.5–6.0%, pH – 8–9. Due to optimization, the grease degradation rate increased by 20–30%. The optimization of drainpipe cleaning technology was achieved in two stages. During the first stage, the experiments were performed in laboratory flasks; during the second stage, optimized cleaning process was tested in a pilot plant. The following optimal parameters were set: pH – 8, amount of bacterial preparation –1.25 l/m2 and harness of water – 0.0 mmol/l. In water of medium hardness, the rate of biodegradation process is 15–20% less. A satisfactory efficiency of grease biodegradation was achieved in the pilot plant: the 86.7% of grease were digested in 21 days. Besides, living microorganisms were detected inside the clean drainpipe. Santrauka Sukurta kompleksinė, efektyvi ir inovacinė nuotekų bei vamzdynų, užterštų riebalais, valymo technologija. Atlikti laboratoriniai eksperimentai, siekiant nustatyti biopreparato, sudaryto iš Enterobacter aerogenes E13, Arthrobacter sp. N3 ir Bacillus coagulans S1, riebalų skaidymo efektyvumą kiek vandenyje, tiek vamzdyje. Gauti rezultatai parodė, kad atrinkti mikroorganizmai intensyviai skaido riebalus iki lengvų, neturinčių nemalonaus kvapo nuosėdų, vandens ir CO2, todėl gali būti taikomi pramonėje. Technologiniam valymo procesui optimizuoti taikyta reakcijos paviršiaus metodologija. Nustatyti optimalūs nuotekų, užterštų riebalais, valymo technologiniai parametrai: riebalų koncentracija – 4,5–6,0 g/l, biopreparato kiekis – 5,5–6,0%, pH – 8–9. Optimizavus procesą, riebalų skaidymo greitis padidėja 20–30 %. Vamzdžių, užterštų riebalais, valymo technologijos optimizavimas atliktas dviem etapais. Pirmajame etape eksperimentiniai tyrimai atlikti kolbose, antrajame etape optimizuotas procesas testuotas valant riebalinius teršalus bandomajame įrenginyje. Nustatyti optimalūs valymo parametrai: pH – 9, biopreparato kiekis – 1,25 l/m2 ir vandens kietis – 0,0 mmol/l. Esant vidutiniam vandens kiečiui biodagradacijos proceso greitis sumažėja 15–20%. Geras riebalų skaidymo efektyvumas pasiektas bandomajame įrenginyje, po 21 paros suskaidyta 86,7 % riebalų. Taip pat ant švaraus vamzdžio sienelių rasta gyvų mikroorganizmų. Резюме Создана комплексная, эффективная и инновационная технология очистки сточных вод и трубопроводов, загрязнённых липидами. С целью проверки эффективности бактериального состава (Enterobacter aerogenes E13, Arthrobacter sp. N3 и Bacillus coagulans S1) для расщепления жиров в воде и водосточной трубе были выполненылабораторные эксперименты. Полученные результаты показали, что отобранные микроорганизмы интенсивнорасщепляют жир до лёгкого осадка без побочного запаха воды и CO2 и могут быть применены в промышленности. Для оптимизации технологических процессов очистки использовался метод математического моделирования.Были определены оптимальные параметры для биологической обработки сточных вод: концентрация жира – 4,5– 6,0 г/л, количество бактериального состава – 5,5–6,0%, pH фактор – 8–9. После оптимизации скорость деградации жира увеличилась на 20–30%. Оптимизация технологии по очистке водосточных труб была выполнена на двухстадиях. На первой стадии эксперименты были выполнены в лабораторных колбах. На второй стадии оптимизационный процесс очистки был проведен в пилотной установке. Были установлены оптимальные параметры: pH фактор – 8, количество бактериального состава – 1,25 л/м2 и жёсткость воды – 0,0 ммол/л. В среднежёсткой водескорость процесса биологического распада была на 15–20% меньше. Хорошая биодеградация жира была установлена в пилотной установке. 86,7% жира было расщеплено за 21 день. Также в чистой водосточной трубе были обнаружены живые микроорганизмы.

The extensive use of antibiotics leads to an increasing number of antibiotic-resistant pathogenic microorganisms. The development of new antimicrobials is needed for clinical, veterinary, and food applications. Bacteriocins are small peptides with antimicrobial activity ribosomally synthesized by bacteria and could be applied as an alternative to classical antibiotics. In this study, the bacteriocin-like (BLIS) peptide, produced by Staphylococcus xylosus was partially purified and main characteristics (pH, thermal stability, resistance to some protease enzymes and molecular weight) were evaluated. Ammonium sulfate precipitation, acetone extraction and ion-exchange chromatography methods were applied for purification of bacteriocin. The activity of bacteriocin was detected using a well diffusion assay method and the amount of protein concentration was estimated by Lowry method. Molecular weight (~ 6 kDa) of purified bacteriocin was determined by sodium dodecyl sulphate polyacrilamide gel electrophoresis (SDS PAGE) method. The highest purification yield (80 %) was obtained using ion-exange chromatography and SP-sepharose as sorbent. The purified bacteriocin remained stable at pH values between 2.0 and 12.0 for 4 h. No decrease in antibacterial activity was estimated after 30 min at 121º C temperature. The purified bacteriocin was resistant to papain, pepsin and trypsin action. The BLIS inhibits a growth of Listeria monocytogenes (93 ± 3.0 %), Bacillus subtilis (85 ± 4.0 %), Pediococcus pentosaceus (79 ± 4.0 %), Staphylococcus aureus (51 ± 5.0 %) and Propionibacterium acnes (70 ± 5 %) up to 24 hours. Such bacteriocin preparation could be applied as antimicrobial agent in medical and food industry.