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Awareness is growing that human health cannot be considered in isolation but is inextricably woven with the health of the environment in which we live. It is, however, under-recognized that the sustainability of human activities strongly relies on preserving the equilibrium of the microbial communities living in/on/around us. Microbial metabolic activities are instrumental for production, functionalization, processing, and preservation of food. For circular economy, microbial metabolism would be exploited to produce building blocks for the chemical industry, to achieve effective crop protection, agri-food waste revalorization, or biofuel production, as well as in bioremediation and bioaugmentation of contaminated areas. Low pH is undoubtedly a key physical–chemical parameter that needs to be considered for exploiting the powerful microbial metabolic arsenal. Deviation from optimal pH conditions has profound effects on shaping the microbial communities responsible for carrying out essential processes. Furthermore, novel strategies to combat contaminations and infections by pathogens rely on microbial-derived acidic molecules that suppress/inhibit their growth. Herein, we present the state-of-the-art of the knowledge on the impact of acidic pH in many applied areas and how this knowledge can guide us to use the immense arsenal of microbial metabolic activities for their more impactful exploitation in a Planetary Health perspective.

Lactic acid bacteria synthesize metabolites that can be used in pharmaceutical, food, water, and dairy industries. Hence, in this study, a novel exopolysaccharide was extracted and isolated from the probiotic strain L. reuteri B2, assessed on possible application as a biosorbent for removal of heavy metals from the contaminated water. Novel exopolysaccharide was characterized using SEM, and TGA/DTG analysis. Our hypothesis was that if this EPS can be used as potentinal biomaterial, than its application for nickel removal from the contaminated water can be performed. After biosorption experiments, the removal efficiency of Ni2+ from the aqueous solution was 92.96%. According to these results, this exopolysaccharide can be considered as a very promising biomaterial for application in different industries, from pharmacy to treatments of contaminted water, Bakterije mlečne kiseline sintetišu metabolite koji se mogu koristiti u farmaceutskoj, prehrambenoj, vodenoj i mlečnoj industriji. S toga, u ovoj studiji je ekstrahovan i izolovan novi egzopolisaharid iz probiotičkog soja L. reuteri B2, koji je testiran za moguću primenu kao biosorbent za uklanjanje teških metala iz kontaminirane vode. Novi egzopolisaharid je okarakterisan korišćenjem SEM i TGA/DTG analize. Naša hipoteza je bila da ako se ovaj EPS može koristiti kao potencijalni biomaterijal, onda se može primeniti za uklanjanje nikla iz kontaminirane vode. Nakon eksperimenata biosorpcije, efikasnost uklanjanja Ni2+ jona iz vodenog rastvora bila je 92,96%. Prema ovim rezultatima, ovaj egzopolisaharid se može smatrati veoma perspektivnim biomaterijalom za primenu u različitim industrijama, od farmacije do tretmana kontaminirane vode

Stillage is a main by-product of the bioethanol industry and, depending on the origin of substrates for bioethanol production, it can be a significant pollutant affecting the profitability of bioethanol production. Directing the stillage towards the production of bio-based chemicals or high-quality feed is a preferred stra- tegy. In this paper, a complete utilization of stillages of different origins was assessed. Thin stillages from bioethanol production from molasses, wasted bread and corn were chemically characterized, evaluated and compared as substrates for lactic acid (LA) and probiotic biomass production by Lactobacil- lus rhamnosus ATCC 7469, while solid fractions of wasted bread and corn stil- lages were analyzed for feed. The impact of pH control using CaCO 3 or NaOH was also examined, both in terms of LA production and valorization of the remains generated in each process.A maximal LA productivity of 1.14 g/(L h) was obtained on thin wasted bread stillage with pH control by NaOH while the number of viable probiotic bacterial cells was above 109 CFU/mL. The com- position of the solid fraction of the wasted bread stillage was complementary with the needs of monogastric animals, while the solid fraction of corn stillage was more adequate for the nutritional requirements of ruminants., Džibra je najznačajniji otpadni ili sporedni proizvod industrije bioetanola. U zavisnosti od porekla supstrata koji se koriste u proizvodnji bioetanola, može biti značajan zagađivač, pa utiče na profitabilnost proizvodnje bioetanola. Upotreba džibre u biotehnološkim postupcima proizvodnje hemikalija ili visoko vredne stočne hrane je poželjna strategija za smanjenje negativnih efekata džibre na životnu sredinu i profitabilnost proizvodn je bioetanola. U ovom radu je analizirana mogućnost kompletnog iskorišćenja džibre. Tečne džibre iz proizvodnje bioetanola na melasi, otpadnom hlebu i kukuruzu su hemijski okarakterisane i upoređene kao supstrati za proizvodnju mlečne kiseline (MK) i probiotske biomase soja Lactobacillus rhamnosus ATCC 7469, dok je čvrsti ostatak hlebne i kukuruzne džibre analiziran kao hrana za životinje. Takođe je ispitan uticaj pH kontrole pomoću CaCO3 ili NaOH sa aspekta proizvodnje MK i sa aspekta iskorišćenja ostataka iz oba procesa. Maksimalna produktivnost MK od 1,14 g/(L h) je dobijena na tečnoj džibri iz otpadnog hleba sa pH kontorolom pomoću NaOH, dok je broj živih pro- biotskih bakterija bio preko 10 9 CFU/mL. Rezultati su pokazali da je sastav čvrste frak- cije otpadne hlebne džibre komplementaran sa potrebama monogastričnih životinja, dok sastav čvrste frakcije kukuruzne džibre više odgovara nutritivnim potrebama preživara.

Dextransucrase (DS) is a glucosyltransferase (E. C. 2.4.1.5) that catalyzes the transfer of glucosyl residues from sucrose to dextran polymer and liberates fructose. This enzyme isassociated with a wide application range of dextran and oligosaccharides. DS production by Leuconostoc mesenteroidesT3 was optimized using a Central Composite Design under the Response Surface Methodology. Three variables were chosen for optimization: distillery stillage, sucrose and manganese concentration. The results showed that sucrose and manganese concentrations had a positive linear effect on DS production while all variable interactions (stillage-manganese, stillage-sucrose, and sucrose-manganese) had significant influences on the DS production. The maximal DS yield of 3.391 +/- 0.131 U cm-3, was obtained in the medium with 64.33 % distillery stillage concentration, 5.30% sucrose concentration and 0.022 % manganese concentration. Our study revealed the potential of distillery stillage combined with sugar beet molasses, supplemented with sucrose and manganese to be employed as a valuable medium growth for lactic acid bacteria and production of DS. Also, taking into consideration the origin of the substrates, utilization of industrial by-products in this way has a great environmental relevance and is in accordance with circular economy.

In this study, we assessed the effects of microwave irradiation of wheat gluten proteins as a pretreatment performed in a microwave reactor that could accurately control process parameters as a function of power and temperature, as well as comparing it with conventional heat treatment. The aim was to identify suitable combinations of partial enzymatic hydrolysis and microwave pretreatment parameters to produce gluten hydrolysates with reduced allergenicity and conserved techno-functional features for food application. FTIR analysis, and total and reactive SH group contents confirmed that the microwave-controlled heating can significantly change the secondary structure and conformation of gluten protein. The microwave treatment had the largest effect at 200 W and 100 degrees C, at which the content of gluten has been reduced by about 2.5-fold. The microwave pretreatment also accelerated the enzymatic hydrolysis of gluten, changing the kinetic profile. The apparent hydrolysis rate constants (k(2)) were 1.00, 3.68, 3.48, 4.64 and 4.17 min(-1) for untreated gluten, and those pretreated with microwave power of 200, 400, 600 and 800 W, respectively. Compared to the heat treatment, it appeared that microwave specific non-thermal effects had a significant influence on the gluten structure and allergenicity and, in combination with the enzymatic hydrolysis, ultimately yielded protein hydrolysates with enhanced antioxidant and functional properties.

Dextransucrase (DS) is a glucosyltransferase (E. C. 2.4.1.5) that catalyzes the transfer of glucosyl residues from sucrose to dextran polymer and liberates fructose. This enzyme isassociated with a wide application range of dextran and oligosaccharides. DS production by Leuconostoc mesenteroidesT3 was optimized using a Central Composite Design under the Response Surface Methodology. Three variables were chosen for optimization: distillery stillage, sucrose and manganese concentration. The results showed that sucrose and manganese concentrations had a positive linear effect on DS production while all variable interactions (stillage-manganese, stillage-sucrose, and sucrose-manganese) had significant influences on the DS production. The maximal DS yield of 3.391±0.131 U cm-3, was obtained in the medium with 64.33 % distillery stillage concentration, 5.30% sucrose concentration and 0.022 % manganese concentration. Our study revealed the potential of distillery stillage combined with sugar beet molasses, supplemented with sucrose and manganese to be employed as a valuable medium growth for lactic acid bacteria and production of DS. Also, taking into consideration the origin of the substrates, utilization of industrial by-products in this way has a great environmental relevance and is in accordance with circular economy., Dekstransaharaza (DS) je glukoziltransferaza (E. C. 2.4.1.5.) koja katalizuje prenos ostataka glukoze iz saharoze u polimer dekstrana, pri čemu se oslobađa fruktoza. Ovaj enzim je povezan sa širokim spektrom primene dekstrana i oligosaharida. Proizvodnja dekstransaharaze pomoću bakterije Leuconostoc mesenteroides T3 optimizovana je metodom odzivnih površina korišćenjem centralnog kompozitnog dizajna. Za optimizaciju su izabrane tri promenljive: koncentracija džibre, koncentracija saharoze i koncentracija jona mangana. Rezultati su pokazali da koncentracije saharoze i jona mangana imaju pozitivan linearni efekat na proizvodnju DS dok su sve interakcije (džibra-Mn2+, džibra-saharoza i saharoza-Mn2+) imale značajan uticaj na proizvodnju DS. Na osnovu eksperimentalnih podataka i numeričke optimizacije, dobijen je maksimalni prinos DS od 3.391 ± 0.131 U cm-3 u podlozi sa 64.33 % džibre, 5.30 % saharoze i 0.022 % jona mangana. Naše istraživanje otkrilo je da se džibra u kombinaciji sa melasom šećerne repe kao i saharozom i dodatkom jona mangana može koristiti kao dragocena hranjiva komponenta za rast bakterija mlečne kiseline i proizvodnju DS. Takođe, uzimajući u obzir poreklo supstrata, upotreba industrijskih nusproizvoda na ovaj način ima veliku ekološku važnost.

Brewer's spent grain (BSG) was used in this study as a support for the immobilization of Lactobacillus paracasei NRRL B-4564, thus enabling the recirculation of immobilized biomass in repeated-batch fermentation. The chemical composition and the energy parameters of the fermented and non-fermented BSG were analyzed and compared. Moreover, the probiotic features of L. paracasei were analyzed to examine the possibility of using fermented BSG as a functional ingredient in ruminant diets. The results obtained indicate that the fermented BSG had significantly higher protein and ash contents, as well as a significantly lower content of fiber fractions. Furthermore, the fermentation process increased the BSG energy content. The analysis of probiotic potential revealed a high tolerance of L. paracasei to pH 2.5 and bovine bile, autoaggregation ability and antimicrobial activity, suggesting that the fermented BSG with immobilized microbial biomass can be used as functional feed in ruminant diets., Globalna potražnja za hranom animalnog porekla raste kao posledica kontinuiranog rasta populacije, urbanizacije i porasta prihoda. Kako bi se zadovoljile potrebe tržišta, upotreba nekonvencionalnih hraniva i sporednih agro-industrijskih proizvoda u ishrani životinja postaje uobičajena praksa. U ovom radu je ispitivan uticaj mlečno-kiselinske fermentacije na kvalitet pivskog tropa kao hraniva za preživare. Pivski trop je korišćen kao nosač za imobilizaciju Lactobacillus paracasei NRRL B-4564, što je omogućilo recirkulaciju imobilisane mikrobne biomase u više uzastopnih šaržnih ciklusa. Po završetku poslednje fermentacione šarže, pivski trop sa imobilisanom biomasom je odvojen od fermentacionog medijuma i osušen, nakon čega su ispitivani hemijski sastav i energetski parametri relevantni za njegovu upotrebu u ishrani preživara. Dodatno, analizirana su probiotiska svojstva L. paracasei, kako bi se u potpunosti sagledala mogućnost primene fermentisanog pivskog tropa kao funkcionalnog hraniva. Utvrđeno je da fermentisani pivski trop ima značajno veći sadržaj proteina i pepela, kao i znatno manji sadržaj svih frakcija vlakana u odnosu na nefermentisane uzorke. Takođe, fermentacija je dovela do povećanja sadržaja energije pivskog tropa. Analizom probiotskih karakteristika, utvrđeno je da L. paracasei ima visoku stopu preživljavanja pri pH 2.5 i u prisustvu goveđe žuči, sposobnost autoagregacije, kao i antimikrobnu aktivnost prema Gram-pozitivnim (Bacillus cereus) i Gram-negativnim (Escherichia coli) patogenim bakterijama. Na osnovu fenotipskih karakteristika L. paracasei, kao i povoljnog uticaja mlečno-kiselinske fermentacije na kvalitet pivskog tropa, može se zaključiti da se fermentisani pivski trop sa imobilisanom mikrobnom biomasom može koristiti kao funkcionalno hranivo u obrocima namenjenim ishrani preživara.

BACKGROUND Brewer's spent grain (BSG), brewer's yeast (BY), malt rootlets (MR), and soy lecithin (SL) are valuable and abundant by-products obtained from brewing, malting, and oil industry, respectively. L-(+)-lactic acid (LA) is organic acid that has a wide range of application. In this study hydrolysate obtained from BSG and MR mixture (BSGMR), was used in combination with SL and BY extract (BYE) in LA fermentation. The aim was to evaluate the effect and to optimize the addition of SL (0.1% and 0.2%) or BYE (10% and 20%) compared with Tween 80 (0.1%) and yeast extract (0.8%), in batch and fed-batch LA fermentation. RESULTS Using optimal SL and BYE concentrations (0.19% and 19.12%, respectively) obtained by response surface methodology (RSM), the highest LA concentration, yield, and volumetric productivity of 28.43 g L-1, 93.03%, and 1.04 g L-1 h(-1), respectively, were achieved in batch fermentation, with further increase using fed-batch fermentation (70.17 g L-1, 94.57%, and 1.22 g L-1 h(-1), respectively). CONCLUSION The results achieved indicated that the combination of industrial by-products, BSG, MR, SL, and BYE can be used as very suitable fermentation media for LA production, and that SL and BYE could be used as cheap replacements for Tween 80 and YE without decreasing fermentation efficiency.

Food contamination by molds is a serious issue in food industry still today. On the other hand, consumers today demand food that is minimally processed and without synthetic preservatives and additives. Therefore, the objective of this paper was to examine the antifungal effect basil and caraway essential oils (EOs) against Penicillium aurantiogriseum FEMK1, P. carneum FEMK2, P. cavernicola FEMK3, P. nalgiovense FEMK4, P. polonicum FEMK5, and Mucor racemosus FEMK6, isolated from the surface of fermented sausages, in vitro and in vivo.Caraway EO showed better antifungal effects in vitro than basil EO. Minimal fungicidal concentration (MFC) of caraway EO for P. aurantiogriseum FEMK1 was 1.5 mu l/mL, and for other species 4.5 mu l/mL, while MFC of basil EO was 9.0 mu l/mL for P. aurantiogriseum FEMK1, P. carneum FEMK2, P. cavernicola FEMK3, and M. racemosus FEMK6. Applied EOs caused macro- and micromorphological changes in the examined molds. EOs applied to the surface of fermented sausage that was artificially inoculated with conidia suspension of P. carneum FEMK2 and P. polonicum FEMK5, has significantly affected the reduction of molds growth. The results obtained in this investigation indicate to possibility of applying EOs in the antifungal protection of fermented sausages.

BACKGROUND Growing challenges of resource depletion, food security and environmental protection are putting stress on the development of biorefinery processes for bioprocessing of residues from food and agro-industry into value-added products. In this study, the simultaneous production of lactic acid (LA) and livestock feed on a combined substrate based on molasses and potato stillage by Lactobacillus paracasei NRRL B-4564 immobilized onto sunflower seed hull (SSH), brewer's spent grain (BSG) and sugar beet pulp (SBP) was studied. RESULTS The highest total LA concentration of 399 g L-1 with overall productivity of 1.27 g L-1 h(-1) was achieved in repeated batch fermentation by SBP-immobilized biocatalyst, followed by BSG- and SSH-immobilized cells. Fermentation improved the content of proteins and ash, and decreased the content of fibers in all three support materials. In addition, the fermentation had favorable effect on in vitro dry matter digestibility and energy values of SSH and BSG. According to assessment of probiotic potential, L. paracasei demonstrated a favorable probiotic profile, exhibiting high resistance to simulated ruminant digestive tract and significant antioxidant and antimicrobial activity. CONCLUSIONS The proposed strategy enables valorization of agro-industrial residues as value-added ruminant feed and simultaneous LA production. Following principles of circular economy, the developed process combines different raw materials and integrates them into a biorefinery process, improving the overall profitability and productivity.

Inhibitory activity of caraway and juniper essential oils was tested against two aflatoxigenic strains (Aspergillus flavus-four isolates and Aspergillus parasiticus-one isolate) using the method of agar plates. A. flavus IKBT and A. flavus IKB isolated from corn flour, A. flavus IKT isolated from peanuts, and A. flavus IKK isolated from flint corn. A. parasiticus CBS 260.67 was obtained from the Centralbureau voor Schimmelcultures (CBS, Utrecht, The Netherlands). The inhibitory effect of essential oils on aflatoxins secretion by A. flavus (isolated from maize flour) was examined in the polenta. Growth of all fungi were completely inhibited at caraway essential oil concentration of 4.5 mu l/g. At this concentration, aflatoxin secretion was completely inhibited in polenta. Juniper essential oil particularly inhibited growth of examined fungi at the applied concentration of 35 mu l/g (from 42.4% to 79.7%). At concentration of 50.0 mu l/g, this oil completely inhibited aflatoxin secretion in polenta. Practical applications The obtained results show that caraway essential oil had significantly better inhibitory effects against A. flavus, A. parasiticus, and aflatoxins production than juniper essential oil, in vitro and in polenta. Future research should point to the possible application of this oil in different types of food and the choice of an efficient method: adding them directly to the product, surface coating of the products, dispersing, applying them in the atmosphere of the package, coating the inner side of the packaging, applying in edible films, or in the form of nanocapsules. In the case of polenta, essential oils can be applied in the packaging atmosphere, by coating the inside of the package, or adding them directly to the polenta.

The application of by-products from the brewing industry in lactic acid (LA) production was investigated in order to replace expensive nitrogen sources (such as yeast extract) with cheaper and renewable nitrogenous materials such as brewer's yeast (BY). In this study, brewer's spent grain (BSG) hydrolysate was used for L-(+)-LA fermentation by Lactobacillus rhamnosus ATCC 7469. The effect of pH control during the fermentation and the addition of various BY contents (5-50 g/L) in BSG hydrolysate on fermentation parameters was evaluated. BY addition significantly increased free amino nitrogen (FAN) concentration (by 25.2% at 5 g/L to 616% at 50 g/L). A strong positive correlation between FAN concentration in the hydrolysate and concentration of L-(+)-LA produced was observed (correlation coefficient of 0.913). A high cell viability of L. rhamnosus ATCC 7469 (1.95-3.32 x 10(9) CFU/mL at the end of fermentation) was achieved in all fermentations with the addition of brewer's yeast. The addition of BY increased L-(+)-lactic acid yield and volumetric productivity up to 8.4% (5 g/L) and 48.3% (50 g/L). The highest L-(+)-LA yield (89%) and volumetric productivity (0.89 g/L h(-1)) were achieved in fermentation of BSG hydrolysate with 50 g/L of BY.

Lactic acid (LA) is a platform chemical which can be produced biotechnologically on agricultural residues, wastes and by-products and further used for production of biodegradable, biocompatible LA polymers. These polymers are mostly used for high-end applications but they have potential for much wider application with decrease in production costs. Available technologies and strategies are reviewed in order to point out the issues, challenges and solutions relevant to increase sustainability and competitiveness of LA production on agricultural residues and wastes. Data on chemical composition, regional and seasonal availability of agricultural residues, wastes and by-products are lacking to provide predictable and effective combining for LA production. Precision agriculture, remote sensing and integration with data on chemical composition can help in better planning and more adequate exploitation of available sources in future. Novel pretreatments for the most abundant lignocellulosic feedstocks, which allow utilization of carbohydrates in LA production and side streams like lignin in other biorefineries are needed. Integration of pretreatment, hydrolysis and fermentation under non-sterile conditions or open fermentation mode should enable easier scale up and decrease energy consumption and costs without sacrificing LA purity. Capital investments in improvement of the available technologies are high. Support from policy makers stimulating production of LA polymers from second and third generation feedstocks will help in research, development and faster adoption on larger scale. For production of LA polymers with tailored properties, it is essential to choose the most productive method for LA production and separation from these complex substrates. The shift in research interest from LA polymerization towards "green" processing of LA polymers products is occurring and that will be the additional driving force for the field in future.

Owing to a wide band gap energy (3.37 eV at RT) and a large exciton binding energy (60 meV), ZnO nanoparticles (ZnONP) have a diverse application, e.g. in electronics, optoelectronics, photocatalysis. Besides, ZnONP have a great potential in medicine for bioimaging, drug/gene delivery or as antimicrobial and anticancer agents. One of suggested governing mechanisms of the mentioned biological activities of ZnONP is based on formation of reactive oxygen species (ROS). When ZnONP absorb photon with energy equal or greater than its band gap, electrons are excited from the valence band (VB) to the conduction band (CB) leaving the holes in VB. Furthermore, the photogenerated holes (h+) and electrons (e-) migrate from bulk to surface. The photogenerated holes at the VB react with water molecules adsorbed at the particle surface to produce hydroxyl radical, while electrons in CB react with oxygen molecules generating anionic superoxide radical O2 -•. Superoxide radicals can be transformed in highly reactive OH• and so on [1]. Derivatives of this active oxygen can damage the bacterial/tumor cells [2]. However, in sufficiency ROS can damage normal cells as well. Thus, an understanding of ZnONP crystal structure-activity relationship and mechanism of ZnONP-related products formation and their consequent activity is crucial for the design of safe ZnONP based biomaterial for application in treating diseases like cancer. A series of ZnONP samples were synthesized by microwave processing of precipitate in the presence of a small amount (5 wt.%) of surfactants CTAB and citric acid. The particles crystallinity and purity were investigated by X-ray diffraction, Raman and ATR-FTIR spectroscopy. The particles morphology and texture properties were observed with field emission scanning electron microscopy (FE–SEM) and nitrogen adsorption–desorption isotherm, respectively. The optical properties were studied using UV–Vis diffuse reflectance and photoluminescence (PL) spectroscopy. ZnONP

Fig. S1. TEM (a) and HRTEM (b) images of amino modified NaYF4:Yb,Er UCNPs. Corresponding FFT/IFFT given as insets in b, confirms that much smaller crystallites notable at the particles surfaces (a) revealed periodic array of cubic alpha phase, (111) plane with d value of 3.140 Å; Fig. S2. XPS spectrum of amino-functionalized NaYF4:Yb,Er UCNPs: survey spectrum and fine-scan spectra of Na 1s, Y 3d, Yb 4d, Er 4d, F 1s and decomposed ones of C 1s, O 1s and N 1s; Fig. S3. Photostability of amino-functionalized up-converting NaYF4:Yb,Er nanoparticles. The emission intensity was traced during 1h