Solid state fermentation of Moringa oleifera leaf meal by mixed strains for the protein enrichment and the improvement of nutritional value

Enrichment of Fruit Peels' Nutritional Value by Solid-State Fermentation with Aspergillus ibericus and Rhizopus oryzae

The fruit processing industry is responsible for disposing of huge amounts of byproducts, especially fruit peels (FPs), which are often discarded in landfills. Using FPs in biotechnological processes contributes to a circular economy, reducing the environmental burden of FPs and increasing the revenue of the fruit processing industry. This study was focused on upgrading the nutritional value of orange (OPs) and banana (BPs) peels by solid-state fermentation (SSF) with filamentous fungi. SSF factors (moisture, fermentation time, inoculum size, ammonium sulfate (AS), and corn steep liquor (CSL)) and fungi species (Aspergillus ibericus and Rhizopus oryzae) were studied by a variable screening Plackett-Burman design. Both fungi grew on untreated FPs, increasing their protein content and antioxidant activity. Moisture, AS, and CSL were further studied by a Box-Behnken design with A. ibericus. Fermented OPs at 70% moisture and 0.005 g/g AS increased their protein content by 200%, whereas BPs at 70% moisture and 0.005 g/g CSL increased by 123%. Fermented peels were enriched in protein, fiber, and minerals, with a low content of carbohydrates and soluble sugars. Fermented OPs and BPs showed higher antioxidant activity than unfermented peels. The SSF of these FPs is an innovative approach that contributes to obtaining rich nutrient-fermented peels for food.

Immunomodulatory, antioxidant, and growth-promoting activities of dietary fermented Moringa oleifera in Nile tilapia (Oreochromus niloticus) with in-vivo protection against Aeromonas hydrophila

BACKGROUND

Moringa oleifera, a well-known medicinal plant, has been used in aquafeed as a dietary supplement. Based on previous studies, insufficient research is available on the dietary supplementation of Nile tilapia with M. oleifera leaf and seed mixtures, specifically the fermented form. Therefore, this study aimed to investigate the efficacy of fermented (FMO) versus non-fermented M. oleifera (MO) leaf and seed mixtures on immunological parameters, antioxidant activity, growth performance, and resistance to A. hydrophila infection after a 30-day feeding trial on Nile tilapia.

METHODS

A total of 180 fingerlings were randomly divided into four groups in addition to the control group (36 fish each, in triplicate). Fish in the tested groups were fed on basal diet supplemented with MO5%, MO10%, FMO5%, and FMO10%, while those in control were fed on basal diet only. After the feeding trial, fish were challenged with A. hydrophila. The immunomodulatory activity of M. oleifera was evaluated in terms of phagocytic and lysozyme activities, immune-related cytokines and IgM gene expression. Antioxidants, and growth-promoting activities were also assessed.

RESULTS

The results revealed that fish supplemented FMO markedly in FMO10% group followed by FMO5%, exhibited significant (P < 0.05) improvement in the tested immunological, hepatic antioxidants, and growth performance parameters. Furthermore, the highest survival rate post-challenge with mild clinical symptoms, and the lowest A. hydrophila bacterial count were reported in these groups. Meanwhile, MO10%-supplementation exhibited the opposite trend.

CONCLUSIONS

The study' conclusion suggests that fermented M. oleifera leaf and seed mixture is a promising growth-promoting and immunostimulatory feed-additive candidate for Nile tilapia and could reduce the losses caused by A. hydrophila infection.

Enrichment of a Plant Feedstuff Mixture's Nutritional Value through Solid-State Fermentation

Plant feedstuffs are the main ingredients of animal feed. Owing to food-feed competition, increasing the utilization efficiency of these feedstuffs is important for animal nutrition. This can be achieved via solid-state fermentation (SSF). SSF of a plant feedstuff mixture (PFM) (25% rapeseed meal, soybean meal, rice bran, and sunflower meal) by three fungi (Aspergillus ibericus MUM 03.29, Aspergillus niger CECT 2088, and Aspergillus niger CECT 2915) resulted in an increase in protein content by 5%, irrespective of fungi, a reduction in cellulose content by 9 to 11%, and of hemicellulose content by 21 to 34%, relative to unfermented PFM. Enzyme production was measured: the highest cellulase (123.7 U/g), xylanase (431.8 U/g), and beta-glucosidase (117.9 U/g) activity were achieved with A. niger CECT 2088. Principal component analysis showed a positive correlation between all fermented PFMs and enzyme production, protein content, digestibility, and fiber reduction. Bioprocessing of the PFM by SSF increased its nutritional value and digestibility, making it more appealing for animal feeds.

Aspergillus co-cultures: A recent insight into their secondary metabolites and microbial interactions

There is an urgent need for novel antibiotics to combat emerging resistant microbial strains. One of the most pressing resources is Aspergillus microbial cocultures. The genome of Aspergillus species comprises a far larger number of novel gene clusters than previously expected, and novel strategies and approaches are essential to exploit this potential source of new drugs and pharmacological agents. This is the first review consulting recent developments and chemical diversity of Aspergillus cocultures and highlighting its untapped richness. The analyzed data revealed that cocultivation of several Aspergillus species with other microorganisms, including bacteria, plants, and fungi, is a source of novel bioactive natural products. Various vital chemical skeleton leads were newly produced or augmented in Aspergillus cocultures, among which were taxol, cytochalasans, notamides, pentapeptides, silibinin, and allianthrones. The possibility of mycotoxin production or complete elimination in cocultivations was detected, which pave the way for better decontamination strategies. Most cocultures revealed a remarkable improvement in their antimicrobial or cytotoxic behavior due to their produced chemical patterns; for instance, weldone and asperterrin whose antitumor and antibacterial activities, respectively, were superior. Microbial cocultivation elicited the upregulation or production of specific metabolites whose importance and significance are yet to be revealed. With more than 155 compounds isolated from Aspergillus cocultures in the last 10 years, showing overproduction, reduction, or complete suppression under the optimized coculture circumstances, this study filled a gap for medicinal chemists searching for new lead sources or bioactive molecules as anticancer agents or antimicrobials.

Effects of Lactobacillus plantarum on Fermentation Quality and Anti-Nutritional Factors of Paper Mulberry Silage

There are few studies on the application of lactic acid bacteria in the reduction of anti-nutrient factors in paper mulberry silage. This study aimed to investigate the effects of different lactic acid bacteria on the fermentation quality and the amount of anti-nutritional factors in paper mulberry silage. Two strains of Lactobacillus plantarum (GX, isolated from paper mulberry silage; GZ, provided by Sichuan Gaofuji Biotechnology Co. Ltd.) were added as silage additives. On days 7, 15, 30 and 60 of the ensiling process, the fermentation quality, and the amount of anti-nutritional factors were measured. Compared with the control group, inoculation with Lactobacillus plantarum could rapidly reduce pH values, leading to lower NH3-N/TN. Besides, it also significantly increased the lactic acid content (p < 0.05). The two strains of L. plantarum significantly reduced the content of hydrolysed tannin, condensed tannin, total tannin, oxalic acid, phytic acid and saponin (p < 0.05). Overall, this study found that the addition of lactic acid bacteria could significantly improve the fermentation quality of paper mulberry and reduce the amount of anti-nutrient factors (p < 0.05).

The role of single cell protein in cellular agriculture

More food needs to be produced for the growing human population, but the possibilities of expanding the area of arable land are limited. Cellular Agriculture is an emerging field of biotechnology, aimed at finding alternatives to agricultural production of various commodities. As a part of Cellular Agriculture, the use of microbes and microalgae as food and feed with high protein content, so-called single cell protein (SCP), is gaining renewed scientific and commercial interest. In this review, we give an introduction to SCP production by heterotrophic microbial species, phototrophs, methanotrophs and autotrophic hydrogen oxidizers, as well as highlight some challenges and the latest developments in the growing SCP industry.

Enhancing the Quality of Total Mixed Ration Containing Cottonseed or Rapeseed Meal by Optimization of Fermentation Conditions

Cottonseed meal (CSM) and rapeseed meal (RSM) are protein sources in livestock feed. However, the applications of both ingredients are limited in diets due to the existence of anti-nutritional factors such as free gossypol and glucosinolate. The aim of this study was to determine the optimal fermentation conditions for reducing anti-nutritional factors and increasing the nutritional value of fermented total mixed rations containing cottonseed or rapeseed meal. An orthogonal design L9 (34) was performed to optimize the fermentation conditions, including fermentation time, temperature, moisture content and microbial strain. Optimum fermentation conditions were performed using different fermentation times (48, 60, 72 h), fermentation temperatures (28 °C, 32 °C, 36 °C), moisture content (40%, 50%, 60%) and microbial inoculations (1 = Bacillus clausii with 1 × 109 CFU/kg DM for CSM or 1 × 1010 CFU/kg DM for RSM; 2 = Saccharomyces cariocanus with 5 × 109 CFU/kg DM; 3 = mixed strain (B. clausii:S. cariocanus ratio 1:1). The results show that the concentration of free gossypol content was reduced (p < 0.05), while the crude protein content was increased (p < 0.05) in CSM through optimum fermentation conditions: time 60 h; temperature 32 °C; moisture content 50% and inoculated with B. clausii (1 × 109 CFU/kg DM) as well as S. cariocanus (5 × 109 CFU/kg DM). Likewise, the concentration of glucosinolate was lowered (p < 0.05) and the crude protein was increased (p < 0.05) in RSM through optimum fermentation conditions: time 60 h; temperature 28 °C; moisture 50% and inoculated with B. clausii (1 × 1010 CFU/kg DM) as well as S. cariocanus (5 × 109 CFU/kg DM). Our findings indicate that the optimal fermentation conditions of total mixed rations with cottonseed meal or rapeseed meal enhance the nutritional value, thereby making them viable and usable feedstuffs for potential use in livestock industries.

A Review of the Effects and Production of Spore-Forming Probiotics for Poultry

Simple Summary

Spore-forming probiotics are widely used in the poultry industry for their beneficial impact on host health. The main feature that separates spore-forming probiotics from the more common lactic acid probiotics is their high resistance to external and internal factors, resulting in higher viability in the host and correspondingly, greater efficiency. Their most important effect is the ability to confront pathogens, which makes them a perfect substitute for antibiotics. In this review, we cover and discuss the interactions of spore-forming probiotic bacteria with poultry as the host, their health promotion effects and mechanisms of action, impact on poultry productivity parameters, and ways to manufacture the probiotic formulation. The key focus of this review is the lack of reproducibility in poultry research studies on the evaluation of probiotics’ effects, which should be solved by developing and publishing a set of standard protocols in the professional community for conducting probiotic trials in poultry.

Abstract

One of the main problems in the poultry industry is the search for a viable replacement for antibiotic growth promoters. This issue requires a “one health” approach because the uncontrolled use of antibiotics in poultry can lead to the development of antimicrobial resistance, which is a concern not only in animals, but for humans as well. One of the promising ways to overcome this challenge is found in probiotics due to their wide range of features and mechanisms of action for health promotion. Moreover, spore-forming probiotics are suitable for use in the poultry industry because of their unique ability, encapsulation, granting them protection from the harshest conditions and resulting in improved availability for hosts’ organisms. This review summarizes the information on gastrointestinal tract microbiota of poultry and their interaction with commensal and probiotic spore-forming bacteria. One of the most important topics of this review is the absence of uniformity in spore-forming probiotic trials in poultry. In our opinion, this problem can be solved by the creation of standards and checklists for these kinds of trials such as those used for pre-clinical and clinical trials in human medicine. Last but not least, this review covers problems and challenges related to spore-forming probiotic manufacturing.

Effect of Solid-State Fermentation on Nutritional Quality of Leaf Flour of the Drumstick Tree (Moringa oleifera Lam.)

The drumstick tree is a fast-growing multipurpose tree with a large biomass and high nutritional value. However, it has rarely been exploited as a protein source. This study investigated solid-state fermentation induced by Aspergillus niger, Candida utilis and Bacillus subtilis to obtain high-quality protein feed from drumstick leaf flour. The results showed that fermentation induced significant changes in the nutritional composition of drumstick leaf flour. The concentrations of crude protein, small peptides and amino acids increased significantly after fermentation. The protein profile was also affected by the fermentation process. Macromolecular proteins in drumstick leaf flour were degraded, whereas other high molecular weight proteins were increased. However, the concentrations of crude fat, fiber, total sugar and reducing sugar were decreased, as were the anti-nutritional factors tannins, phytic acid and glucosinolates. After 24 h fermentation, the concentrations of total phenolics and flavonoids were increased. The antioxidant capacity was also significantly enhanced.