Enzymatic Breakdown Research Articles

Study of Advanced Techniques for Inquisition, Segregation and Removal of Microplastics from Water Streams: Current Insights and Future Directions

The present research covers different analytical methods utilized for the diagnosis and characterization of microplastics (MPs) in water and wastewater, such as particle size distribution analysis, and focuses on the sources and forms of MPs in receiving environments. First, we look at the most recent collection techniques, which include a variety of spectroscopic, chromatographic, and microscopic approaches used to identify and measure microplastics in water samples. We then investigate separation techniques designed to separate microplastics from diverse environmental matrices. This involves applying existing methods of separation based on density, such as centrifugation, flotation, and sedimentation, as well as more recent ones, like the use of microfluidic devices and materials for selective adsorption. Lastly, we look into removal methods aimed to reduce the buildup of microplastics in aquatic environments. These include enzymatic breakdown, coagulation/flocculation, and filtering, among other physical, chemical, and biological techniques.

Bioplastic films from cassava peels: Enzymatic transformation and film properties

Annually, millions of tons of cassava peels are generated as agro-waste. This research repurposed entire cassava peels into biodegradable films as a sustainable alternative to single-use plastics. Enzymes (cellulase, xylanase, and glucanase) were employed to catalyze the process, and cassava peels were effectively converted into films, which exhibited comparable or even better mechanical properties and water resistance to commercial packaging materials. The films also presented high water solubility of 44–50% and good light barrier properties, with 15–23% transmittance values for visible light and less than 3% for UV light. Extended enzymatic treatment time resulted in films characterized by increased elasticity, solubility, water resistance, transparency, and smoother surfaces, which can be attributed to the enzymatic breakdown of cassava peel fibers into smaller saccharide units. The optimal enzymatic treatment time was found to be 4 h which produced films with favorable mechanical characteristics, barrier properties, and solubility. A sustainable and ecologically-friendly approach is provided to fully harness cassava peels in fabricating packaging films, particularly suited for food items necessitating dissolution in water.

Auxiliary Substances for Enhancement of Complexation Efficiency and Dissolution Rate of Drug-Cyclodextrin Complexes

Background: Enzymatic starch breakdown yields 1, 4-linked D-glucopyranoside subunits, which are the building blocks of the cyclodextrin (CD) family of macromolecules. β-Cyclodetrins (β-CDs) have the capability to improve the solubility of partially soluble drugs, as well as their permeability across biological membranes and stability. However, factors like limited solubility, high cost of derivatives and their toxicity at high concentrations has directed the researchers toward multicomponent inclusion complexes (MCIC). Introduction: Incorporating auxiliary substances (AS) leads to MCIC formation during complexation. The auxiliary agent interacts at the molecular level with the CDs, enhances the complexation competence of β-CD or its derivatives, and minimizes the amount required for solubilization of poorly soluble drugs. They also enhance stability of drug-CD complex. Due to these advantages, the popularity of MCIC has increased amongst formulation scientists. Conclusion: This review describes various AS that could be used to prepare MCIC to expand solubility and other properties of drugs and minimize cost of related formulation.

Boosting the Biodegradation and Bioactivity of PBS‐DLS Copolymers via Incorporation of PEG

AbstractBiodegradable polymers play a crucial role in the development of materials for biomedical applications. This study investigates the enzymatic biodegradation, bioactivity, and cytotoxicity of poly(butylene succinate‐dilinoleic succinate) (PBS‐DLS) copolymers modified with poly(ethylene glycol) (PEG). Two copolymer variations with different segmental compositions (70 wt.% and 60 wt.% of hard segments) are synthesized. After modifying the copolymers with PEG, the presence of a lipase catalyst accelerated degradation after 20 days, evidenced by reduced residual content. Gel permeation chromatography analysis showed up to 40% decrease in molecular weight, while gravimetric analysis indicated a mass loss of up to 10%. Morphological examination revealed that the enzymatic breakdown, facilitated by hydrolase activity (boosted by the presence of PEG), resulted in surface erosion, holes, and changes in spherulitic morphology. Bioactivity studies demonstrated the formation of biomimetic calcium/phosphate (Ca/P) crystals. Copolymers with higher crystallinity (70 wt.% hard segments) favored tricalcium phosphate‐like crystal formation, while those with lower crystallinity (60 wt.% hard segments) are more susceptible to hydroxyapatite precipitation. In vitro cytotoxicity tests exhibited excellent cell viability and attachment for all copolymers. The ability to control degradation through PEG modification, along with their bioactivity and cell compatibility, positions them as promising candidates for diverse biomedical applications.

Enzyme‐assisted extraction of rapeseed oil with minimum water addition: a proof‐of‐concept study

SummaryThe increased demand for vegetable oils calls for new strategies for enhancing the yield of mechanical oil extraction, preferably without the use of potentially hazardous solvents such as n‐hexane. Enzyme‐assisted oil extraction has been studied under aqueous conditions, where the oil recovery was enhanced due to the partial enzymatic breakdown of cell wall compounds. However, this process is often not feasible for industrial applications, where mechanical pressing of dry seeds is implemented. This study provides a proof‐of‐concept for enzyme‐assisted rapeseed oil extraction with minimum water addition (1 mL per 100 g rapeseeds). The application of cellulytic and pectolytic enzymes increased the reducing sugar content as a result of the carbohydrate breakdown. The oil recovery in the mechanical pressing was increased significantly from ~60% to ~65%, and the quality of the oils was not significantly affected by the enzyme treatment.

Unlocking the Potential of RNA Nanoparticles: A Breakthrough Approach to Overcoming Challenges in Colon Cancer Treatment.

Globally, one of the leading causes of cancer-related deaths is colon cancer. As this form of cancer has a tremendous potential to metastasize, effective treatment is complicated and sometimes impossible. Despite the improvement of conventional chemotherapy and the advent of targeted therapies, overcoming multi-drug resistance (MDR) and side effects remain significant challenges. As a therapeutic intervention for targeted gene silencing in cancer, RNA technology shows promise and certain RNA-based formulations are currently undergoing clinical studies. Various studies have reported that RNA-based nanoparticles have demonstrated substantial promise for targeted medication delivery, gene therapy, and other biomedical applications. However, using RNA as a therapeutic tool presents severe limitations, mainly related to its low stability and poor cellular uptake. Nanotechnology offers a flexible and tailored alternative due to the difficulties in delivering naked RNA molecules safely in vivo, such as their short half-lives, low chemical stability, and susceptibility to nuclease degradation. In addition to shielding RNA molecules from immune system attacks and enzymatic breakdown, the nanoparticle-based delivery systems allow RNA accumulation at the tumor site. The potential of RNA and RNA-associated nanomedicines for the treatment of colon cancer, as well as the prospects for overcoming any difficulties related to mRNA, are reviewed in this study, along with the current progress of mRNA therapeutics and advancements in designing nanomaterials and delivery strategies.

Dynamic Microparticle Assembly at the Interface of Chemoresponsive Liquid Crystal Droplets.

The confinement of liquid crystals (LCs) in spherical microdroplets results in exotic internal configurations and topological defects in response to physical and chemical stimuli. Recent exploration into the placement of colloids on the surface of LC microdroplets has led to the design of a new class of functional materials with patterned surface properties. It is established that the placement of a colloid on a LC droplet surface can pin the topological defect at the interface, thereby restricting changes in the LC configuration. Herein, we build upon the handful of reports published to provide a fundamental understanding of the colloid positioning in response to external stimuli. Using polystyrene (PS) colloids, we explored the dynamics of particle self-assembly in response to an interfacial enzymatic breakdown of poly-l-lysine by trypsin. We found that for a significant population of droplets, the positioning of the colloid is unaffected by the changes in the internal ordering of LC. Inspired by the new observations, we delved deeper to understand the role of interfacial stabilizers in modulating the preferential alignment of LC and the placement of colloidal microparticles. We also demonstrated that for a certain population of droplets, the positioning of the colloids remains unperturbed in response to multistep reversible adsorption of interfacial amphiphiles. Our findings reveal interesting possibilities of correlating the stimuli-responsive switching of internal configurations of LC with colloid placement on the particle-decorated LC droplets.

Eco-friendly approaches for mitigating plastic pollution: advancements and implications for a greener future.

Plastic pollution has become a global problem since the extensive use of plastic in industries such as packaging, electronics, manufacturing and construction, healthcare, transportation, and others. This has resulted in an environmental burden that is continually growing, which has inspired many scientists as well as environmentalists to come up with creative solutions to deal with this problem. Numerous studies have been reviewed to determine practical, affordable, and environmentally friendly solutions to regulate plastic waste by leveraging microbes' innate abilities to naturally decompose polymers. Enzymatic breakdown of plastics has been proposed to serve this goal since the discovery of enzymes from microbial sources that truly interact with plastic in its naturalistic environment and because it is a much faster and more effective method than others. The scope of diverse microbes and associated enzymes in polymer breakdown is highlighted in the current review. The use of co-cultures or microbial consortium-based techniques for the improved breakdown of plastic products and the generation of high-value end products that may be utilized as prototypes of bioenergy sources is highlighted. The review also offers a thorough overview of the developments in the microbiological and enzymatic biological degradation of plastics, as well as several elements that impact this process for the survival of our planet.

Insect Gut Microbiota and Pesticide Degradation in Response to Innate Metabolites- a Review

Insects host a diverse microbiota in their gut, encompassing bacteria, fungi, viruses, and archaea, influencing their physiology, nutrition, and overall health. The composition of these microbial communities varies with factors like insect species, diet, and the environment. Insect gut microbiota serve pivotal roles such as aiding digestion, synthesizing essential nutrients, safeguarding against pathogens, and detoxifying toxins, including insecticides. A particularly promising facet of their function lies in influencing the metabolism of insecticides. These gut microbiotas can either augment or diminish insecticide toxicity through mechanisms like enzymatic breakdown, sequestration, target site alteration, or modulation of the insect's immune response. Understanding these interactions is paramount for devising sustainable pest management strategies. This review explores into insect gut microbiota, their impact on insecticide susceptibility, and the potential use of microbial metabolites in eco-friendly pest control. We explore pesticide degradation mechanisms, the consequences of microbiota disruption on susceptibility, and the role of microbiota-produced metabolites in shaping pesticide efficacy. Ultimately, we highlight the potential of microbiota manipulation as a strategy to enhance insecticide effectiveness and combat pesticide resistance in pest management.

Malondialdehyde: A Toxic Stress Marker for Periodontitis

Recently, it has been discovered that one of the primary causes of a variety of inflammatory illnesses, including periodontitis, is an excess of Reactive Oxygen Species (ROS). It is recognised that the host’s response to pathogens plays an equal or even bigger part in determining how connective tissue breaks down. The process of Polymorphonuclear (PMN) phagocytosis greatly increases ROS formation through the metabolic pathway known as the “respiratory burst.” Because the antioxidant defense system is unable to neutralise these high levels or activities of ROS, Oxidative Stress (OS) and tissue damage ensue. ROS can directly affect tissue through Lipid Peroxidation (LPO), Deoxyribonucleic Acid (DNA) damage, protein breakdown, and the oxidation of essential enzymes. Numerous aldehydes can be produced as byproducts of LPO, including Malondialdehyde (MDA), propanal, hexanal, and 4-Hydroxynonenal (4-HNE). They can be detected in bodily fluids and suggest a pro-oxidant state. MDA is a by-product created by the enzymatic or non enzymatic breakdown of Arachidonic Acid (AA) and larger Polyunsaturated Fatty Acids (PUFAs). MDA is the most studied OS tissue damage indicator. After it is formed, MDA can either be broken down by enzymes or combine with DNA or proteins in cells and tissues to form adducts that can cause harm to biological molecules.

Probing the Protein-Excipient Interaction in the Orally Delivered Protein by Solid-State Hydrogen-Deuterium Exchange Mass Spectrometry and Molecular Dynamics.

The oral administration of protein therapeutics in solid dosage form is gaining popularity due to its benefits, such as improved medication adherence, convenience, and ease of use for patients compared to traditional parental delivery. However, formulating oral biologics presents challenges related to pH barriers, enzymatic breakdown, and poor bioavailability. Therefore, understanding the interaction between excipients and protein therapeutics in the solid state is crucial for formulation development. In this Letter, we present a case study focused on investigating the role of excipients in protein aggregation during the production of a solid dosage form of a single variable domain on a heavy chain (VHH) protein. We employed solid-state hydrogen-deuterium exchange coupled with mass spectrometry (ssHDX-MS) at both intact protein and peptide levels to assess differences in protein-excipient interactions between two formulations. ssHDX-MS analysis revealed that one formulation effectively prevents protein aggregation during compaction by blocking β-sheets across the VHH protein, thereby preventing β-sheet-β-sheet interactions. Spatial aggregation propensity (SAP) mapping and cosolvent simulation from molecular dynamics (MD) simulation further validated the protein-excipient interaction sites identified through ssHDX-MS. Additionally, the MD simulation demonstrated that the interaction between the VHH protein and excipients involves hydrophilic interactions and/or hydrogen bonding. This novel approach holds significant potential for understanding protein-excipient interactions in the solid state and can guide the formulation and process development of orally delivered protein dosage forms, ultimately enhancing their efficacy and stability.

Bread clip ingestion resulting in small bowel perforation: A case report

Bread clip ingestion is an avoidable, all too common cause of an acute surgical abdomen. Patients present with various symptoms ranging from dysphagia, bleeding, perforation, and death with few cases successfully passing without causing significant damage. The patient in this case had gastrointestinal symptoms for over 2 months with associated weight loss, mimicking a time length of malignancy. The clip was lodged in the small bowel, which is often the case. This study presents an uncommon presentation of symptoms with evidence of the varying degrees of bread clip injury, preceding perforation. Plastic resists enzymatic breakdown in the gastrointestinal tract, and its unique shape contributes to the bowel wall getting caught in between its jaws, followed by dislodgment through peristalsis, and eventual perforation. Despite publicity in Australian news articles, manufacturers and supermarkets still utilize products with plastic bread clips and present an avoidable health hazard to patients in this country.

CELLULASE ACTIVITY OF RIZOSFER BACTERIA OF KETAPANG PLANTS (Terminalia catappa L.)

Cellulose, a natural biopolymer produced by plants, undergoes enzymatic breakdown by cellulase, cleaving the monomer's β-1,4 glycosidic bonds. Cellulolytic bacteria, producers of cellulase, can be isolated from plant rhizospheres, like Ketapang (Terminalia catappa L.), abundantly found in the Biology Department at Universitas Sriwijaya, South Sumatra, Indonesia. This study aimed to isolate cellulolytic bacteria from Ketapang rhizosphere soil and assess their cellulase activity. The spread plate method on selective Carboxy Methyl Cellulose Agar (CMC agar) was used for bacterial isolation, and cellulase activity was measured using the DNS method (3.5-dinitro salicylic acid). Results yielded 22 isolates of cellulolytic bacteria capable of growth on selective CMC agar. Thirteen isolates, identified through a screening test, produced cellulase, forming clear zones post-addition of 0.1% Congo Red and 1 M NaCl. Cellulolytic activity indices for these isolates ranged from 0.02 to 2.6 mm. The highest indices (IAS) and cellulase activities were observed in BS10, BS4, and BS22, with IAS values of 2.64, 2.12, and 1.71, and cellulase activities of 354.99 U/ml, 9.42 U/ml, and 9 U/ml, respectively. Identification results suggested that isolate BS10 bore similarities to the genus Zoogloea, while isolates BS4 and BS22 showed similarities to the genus Bacillus.

The Relationship between the Sugar Preference of Bacterial Pathogens and Virulence on Plants

Plant pathogenic bacteria colonize plant surfaces and inner tissues to acquire essential nutrients. Nonstructural sugars hold paramount significance among these nutrients, as they serve as pivotal carbon sources for bacterial sustenance. They obtain sugar from their host by diverting nonstructural carbohydrates en route to the sink or enzymatic breakdown of structural carbohydrates within plant tissues. Despite the prevalence of research in this domain, the area of sugar selectivity and preferences exhibited by plant pathogenic bacteria remains inadequately explored. Within this expository framework, our present review endeavors to elucidate the intricate variations characterizing the distribution of simple sugars within diverse plant tissues, thus influencing the virulence dynamics of plant pathogenic bacteria. Subsequently, we illustrate the apparent significance of comprehending the bacterial preference for specific sugars and sugar alcohols, postulating this insight as a promising avenue to deepen our comprehension of bacterial pathogenicity. This enriched understanding, in turn, stands to catalyze the development of more efficacious strategies for the mitigation of plant diseases instigated by bacterial pathogens.

Molecular basis for the catalytic mechanism of human neutral sphingomyelinases 1 (hSMPD2)

Enzymatic breakdown of sphingomyelin by sphingomyelinase (SMase) is the main source of the membrane lipids, ceramides, which are involved in many cellular physiological processes. However, the full-length structure of human neutral SMase has not been resolved; therefore, its catalytic mechanism remains unknown. Here, we resolve the structure of human full-length neutral SMase, sphingomyelinase 1 (SMPD2), which reveals that C-terminal transmembrane helices contribute to dimeric architecture of hSMPD2 and that D111 − K116 loop domain is essential for substrate hydrolysis. Coupled with molecular docking, we clarify the binding pose of sphingomyelin, and site-directed mutagenesis further confirms key residues responsible for sphingomyelin binding. Hybrid quantum mechanics/molecular mechanics (QM/MM) molecular dynamic (MD) simulations are utilized to elaborate the catalysis of hSMPD2 with the reported in vitro substrates, sphingomyelin and lyso-platelet activating fator (lyso-PAF). Our study provides mechanistic details that enhance our knowledge of lipid metabolism and may lead to an improved understanding of ceramide in disease and in cancer treatment.

Differential expression of urease genes and ureolytic activity of uropathogenic Escherichia coli and Pseudomonas aeruginosa isolates in different nutritional conditions.

Uropathogens have adaptation strategies to survive in the host urinary tract by efficiently utilizing and tolerating the urinary metabolites. Many uropathogens harbour the enzyme urease for the breakdown of urea and the enzymatic breakdown of urea increases the pH and facilitate the struvite crystallization. In this study, the differential urease activity of uropathogenic Escherichia coli and Pseudomonas aeruginosa strains was investigated under different nutritional conditions. The experiments included measurement of growth, pH, urease activity, NH4-N generation and urease gene (ureC) expression among the bacterial strains under different conditions. Further, the implications of urea breakdown on the struvite crystallization in vitro and biofilm formation were also assessed. The study included urease positive isolates and for comparison urease negative isolates were included. Compared to the urease negative strains the urease positive strains formed higher biofilms and motility. The urease positive P. aeruginosa showed significantly higher (p < 0.01) pH and urease activity (A557-A630) compared to E. coli under experimental conditions. Further, supplementation of glucose to the growth media significantly increased the urease activity in P. aeruginosa and in contrast, it was significantly lower in E. coli. The expression profile of urease gene (ureC) was significantly higher (p < 0.001) in P. aeruginosa compared to E. coli and was consistent with the biochemical results of the urease activity under the nutritional conditions. The differential urease activity under two nutritional conditions influenced the biogenic struvite crystallization. It correlated with the urease activity showing higher crystallization rate in P. aeruginosa compared to E. coli. The results highlight the differential urease activity in two common uropathogens under different nutritional conditions that may have significant role on the regulation of virulence, pathogenicity and in the kidney stone disease.

Urokinase-type plasminogen activator (uPA) regulates invasion and matrix remodelling in colorectal cancer

BackgroundCancer cells remodel their local physical environment through processes of matrix reorganisation, deposition, stiffening and degradation. Urokinase-type plasminogen activator (uPA), which is encoded by the PLAU gene, is an extracellular proteolytic enzyme known to be involved in cancer progression and tumour microenvironment (TME) remodelling. Perturbing uPA therefore has a strong potential as a mechano-based cancer therapy. This work is a bioengineering investigation to validate whether 1) uPA is involved in matrix degradation and 2) preventing matrix degradation by targeting uPA can reduce cancer cell invasion and metastasis. MethodsTo this aim, we used an engineered 3D in vitro model, termed the tumouroid, that appropriately mimics the tumour’s native biophysical environment (3 kPa). A CRISPR-Cas9 mediated uPA knockout was performed to introduce a loss of function mutation in the gene coding sequence. Subsequently, to validate the translational potential of blocking uPA action, we tested a pharmacological inhibitor, UK-371,801. The changes in matrix stiffness were measured by atomic force microscopy (AFM). Invasion was quantified using images of the tumouroid, obtained after 21 days of culture. ResultsWe showed that uPA is highly expressed in invasive breast and colorectal cancers, and these invasive cancer cells locally degrade their TME. PLAU (uPA) gene knock-out (KO) completely stopped matrix remodelling and significantly reduced cancer invasion. Many invasive cancer gene markers were also downregulated in the PLAU KO tumouroids. Pharmacological inhibition of uPA showed similarly promising results, where matrix degradation was reduced and so was the cancer invasion. ConclusionThis work supports the role of uPA in matrix degradation. It demonstrates that the invasion of cancer cells was significantly reduced when enzymatic breakdown of the TME matrix was prevented. Collectively, this provides strong evidence of the effectiveness of targeting uPA as a mechano-based cancer therapy.

Abstract 16786: Integrative Omics in Failing Myocardium Highlights Metabolic Substrate Utilization Defects in Human Heart Failure

Introduction: Changes in substrate utilization may be a biomarker of, or a contributor to, heart failure with reduced ejection fraction (HFrEF). Previous work has described circulating metabolites, proteins and transcripts that reflect myocardial bioenergetics, but direct assessment in relevant tissues is lacking. Here, we leverage integrative omics to identify tissue-level biomarkers and pathways of HFrEF that may play a role in pathogenesis. Methods: Myocardial tissue was obtained from 27 HFrEF donors and 21 non-failing hearts (noHF) from Duke University and the University of Colorado Medical Centers. Targeted (n=139 metabolites) and nontargeted (Metabolon, n=817) metabolic profiling was performed; in addition, 496 proteins were assayed (Olink) and ~31,000 transcripts were quantified via RNA sequencing. Individual metabolites were tested for association with HFrEF in models adjusted for age, sex and diabetes. Metabolomics, proteomics and RNA-seq data were integrated using block sparse partial least squares discriminant analysis (sPLS-DA) to identify correlated biomarkers that discriminate HFrEF from noHF hearts. Results: The targeted metabolomics platform primarily assayed metabolic fuel substrate pathways; 71 analytes (51%) were associated with HFrEF after controlling the false discovery rate (FDR) at 5%. Medium- and long-chain acylcarnitines (C10s-C18s) were significantly lower in tissue from failing hearts, while branched-chain amino acids (BCAA) and ketoacids were higher. In the nontargeted set, 293 metabolites (36%) differed between HFrEF and noHF. BCAA and acylcarnitine associations were recapitulated along with a decrease in malonylcarnitine. The sPLS-DA model selected 25 targeted and 50 nontargeted metabolites, 35 proteins and 35 transcripts, and successfully discriminated HFrEF from no HF (balanced error rate = 3.2%). 39/186 tested KEGG pathways were overrepresented in these analytes, including fatty acid metabolism (FDR q=0.002). Conclusions: Analysis of tissue-level metabolites suggests both decreased use of fatty acids as a fuel and disrupted enzymatic breakdown of BCAAs in the failing heart, while integrative omics pathway analysis also supports the association of disrupted fatty acid metabolism with HF.

Antioxidant, Antiinflammatory, and Anti Uric Acid Bioactivity Correlation of some Family Acanthaceae Plants (A Review)

Uric acid is a naturally occurring antioxidant that is produced in the body as a byproduct of the enzymatic breakdown of xanthine. Inflammation of the blood vessel cells in the human body can be brought on by abnormally high amounts of uric acid in the serum. An acute inflammatory response often manifests with symptoms similar to those of gout attacks. XO is a major contributor to the production of superoxide free radicals, which are a factor in chronic inflammatory diseases. Existing drugs have been used to treat gout and inflammatory diseases, but have negative effects in humans. Medicinal plants are a source of active chemicals, which are particularly significant in the process of developing new medications due to the variety and distinctive chemical structures of these active compounds. Justicia gendarussa, Andrographis paniculata (Burn.f.) Nees, Ruellia tuberosa L, and Clinacanthus nutans Lindau are examples of plant species in the Acanthaceae family. The results of existing publications show that the bioactive compounds contained in these plants have a relationship between antioxidant activity, anti-uric acid and anti-inflammatory properties.

Influence of the use of enzymes and microelements in the rations of steers of different breeds when fattening on their productivity

Basic nutrients in the form in which they are found in feed cannot be absorbed by animals without enzymatic breakdown. Therefore, for more efficient use of nutrients in the body of animals, biological catalysts or enzymes are necessary. In order to maintain normal vital processes of the body, metabolism and increase productivity, minerals are needed. The importance of microelements in the feeding of farm animals has already been proven and accepted, and now no ration can do without their inclusion. The purpose of the research was to study the infl uence of various enzymes, as well as in combination with microelements in the ration of steers of diff erent breeds during fattening, on their productivity and meat quality. For the experiment newborn bulls were selected and groups were formed per 10 heads in each according to the principle of analogues. The 1st control group included steers of Bestuzhev breed, the 2nd experimental group included steers of Black-and-White breed, the 3rd experimental group included steers of Simmental breed and the 4th experimental group included crossbred steers of Simmental×Ayrshire. It was established that the best ability to transform feed protein into meat protein was characteristic of steers of the 3rd experimental group (Simmental breed), which were superior to their herdmates of control group by 1,58 abs.%, and for others the advantages were slightly lower 0,78–1,12 abs.%. Thus, the use of enzymes in the ration of steers of diff erent breeds for fattening in combination with microelements in relation to the capabilities of the local feed supply and the actual chemical composition of feed made it possible to increase the consumption of basic nutrients by animals, improved their digestibility and increased the beef productivity of steers.