De EU en Nederland streven naar significante reducties in broeikasgas- en stikstofemissies tegen 2030. De Nederlandse melkveehouderij draagt met respectievelijk 36% en 48% bij aan de broeikasgasuitstoot en de ammoniakemissies van de landbouw. Het aanzuren van mest met zwavelzuur, zoals in Denemarken, is effectief maar kostbaar. Dit onderzoek evalueert de haalbaarheid van biologisch aanzuren van dierlijke mest met melasse als alternatief, met als doel het verminderen van emissies en het verbeteren van mestverwaarding.Op een melkveehouderij in Someren met circa 100 koeien werd een experiment uitgevoerd waarbij een kleinere mestkelder werd biologisch aangezuurd met melasse en een grotere kelder als controle diende. Beide kelders werden op 6 november 2023 nagenoeg leeggepompt en aan de kleine kelder werd 12% melasse (op initiële hoeveelheid mest basis) toegevoegd. De pH in de aangezuurde mestkelder daalde van 8,1 naar 5,5 in 13 dagen en stabiliseerde op 4,7. Na 9 weken steeg de pH naar 6,0. De aangezuurde dunne fractie bevatte significant meer fosfaat (61%) en de biogasopbrengst steeg met 43% ten opzichte van de controle.Dit onderzoek bevestigt de hypothese dat het toevoegen van organische (rest)stromen aan mestkelders effectief is om methaan- en ammoniakemissies te verlagen en de mestverwaarding te verbeteren. Daarnaast is de aanpak passend binnen de huidige bedrijfsvoering inclusief de regelgeving. De biogasproductie nam significant toe waardoor de mestverwaarding verbeterde.Aanbevolen wordt om de pH van drijfmest rond 5,5 te houden, het verzuringsproces eventueel op te starten met een organisch zuur, en verder onderzoek te doen naar optimale melassedosering, frequenter mengen, en inzet van alternatieve suikerrijke resstromen. Voor borging van het proces zijn implementatie van een pH-monitoringssysteem en aanvullende emissiemetingen noodzakelijk.
MULTIFILE
This study aimed to evaluate technological (acidification, proteolysis, lipolysis, resistance to low pH, NaCl, and bile salts) and biopreservation (antimicrobial activity against foodborne pathogens) features of 1002 LAB by high throughput screening (HTS) methods. The LAB was isolated from 11 types of Brazilian artisanal cheeses (BAC) marketed in the main 5 producing regions. Remarkable intra-species variability in acidification rates have been found, which was most pronounced between isolates from Mina's artisanal cheeses, Caipira and Coalho cheeses. Lacticaseibacillus paracasei and Levilactobacillus brevis showed the fastest acidification rate; however, all isolates showed slower acidification rates than a lactococcal control strain (4.3 × lower). When testing inhibitory effects, > 75% of LAB isolates could inhibit the growth of Staphylococcus aureus ATCC 19095 and Listeria monocytogenes ATCC 7644. Two of these isolates, identified as Lactiplantibacillus plantarum and Lentilactobacillus buchneri, the sterile and neutral supernatants alone, were sufficient to inhibit L. monocytogenes growth. Principal component analysis (PCA) allowed the identification of functional groups based on proteolytic and lipolytic activity, osmotic stress resistance, and inhibition of L. monocytogenes. The type of cheese the isolates were recovered from influenced properties such as anti-listerial compounds and lipolytic enzyme production. The use of HTS and multivariate statistics allowed insights into a diverse set of LAB technological and biopreservation properties. These findings allow a profound knowledge of the heterogeneity of a large set of isolates, which can be further used to design starter cultures with varied and combined properties, such as biopreservation and technological features. Besides that, HTS makes it possible to analyze a vast panel of LAB strains, reducing costs and time within laboratory analysis, while avoiding the loss of information once all LAB are tested at the same time (differently from the traditional labor-intensive approach, in which a few numbers of strains is tested per time).
DOCUMENT
Worldwide, plastic cups are used for serving drinks. Some typical examples of large-scale consumption are large concerts and festivals. As a part of the BIOCAS project, which focusses on the valorization of biomass through various routes, a PHA biobased festival cup was developed and created to reduce the impact of current fossil plastics. The role of VHL was to assess the environmental impact. The aim of the report is to inform the BIOCAS-partners about the use of plastic cups, and address the environmental impact in comparison with other types of biobased plastic cups and fossil-based cups. This report can serve as a basis for making choices within all different types of (plastic/biobased) cups. Besides, it can be used as a public communication tool about the environmental impact of different types of (plastic/biobased) cup applications.
MULTIFILE
Microbes like bacteria and fungi can grow on almost everything, including e.g. on a music CD made of aluminum and polycarbonate. How? By producing an optimal mixture of effective enzymes that degrade the material on which the microbes thrive. In this project we want to find and characterize microbes that have the ability to digest one of the most commercially successful but at the same time hard-to-degrade materials: furan-based bio-composite resin. To help the microbes to degrade this recalcitrant material, we first must open up the complex resin structure by using (mild) acidification, grinding, and/or UV light. Thus, with this project we aim to find an effective and sustainable way to safely and effectively dispose and recycle used bio-composite resins. Our findings will help to increase the circularity of bio-composite materials and as such decrease the environmental waste pressure.
