Potato Protein Research Articles

Effects of different physical factors on potato protein-chitosan complexes considering Hofmeister series and Maillard reaction.

Potato protein possesses strong potential for application in the food industry due to its outstanding nutritional and functional properties. However, the inevitable industrial processing often brings adverse effects. The use of a polysaccharide and protein complex is a promising way to improve the performance of potato protein. This work aimed to investigate the effects of different physical factors on the potato protein/chitosan (PP/CS) complex system. The addition of NaCl was not conductive to the formation of PP/CS complexes, resulting in significantly decreased peak turbidities from 1.29 to 0.75. The effect of different ions on PP/CS system matched with the Hofmeister series in the following order: Li+ > Control > Na+ > K+ ; SCN- > I- > NO3 - > Br- ≈ Control > Cl- > SO4 2- , among which the salting-in ions (Li+ , Br- , NO3 - , I- and SCN- ) tended to promote the formation of PP/CS complexes. The turbidity increased significantly when the reaction temperature rose to 45 °C and above, and peak turbidity was obtained at lower pH values. The PP/CS system reaction at 45 °C led to the highest whiteness value, and the Maillard reaction could occur when the temperature was above 45 °C. The results of the present study confirmed that different physical factors led to strong influences on PP/CS complexes, especially when considering the Hofmeister series and the Maillard reaction. These findings could have significant implications for the utilization of potato protein in complex food systems. © 2023 Society of Chemical Industry.

Assembly of plant-based meat analogs using soft matter physics: A coacervation-shearing-gelation approach

High-energy processing equipment, like extruders or shear cells, are normally required to create fibrous plant-based meat analogs with textures and mouthfeels designed to mimic those of real meat. Here, we propose a simple low-energy method of creating fibrous structures using a soft matter physics approach, which involves complex coacervation, shearing, and gelation of protein/polysaccharide mixtures. A mixture of potato protein and gellan gum was used to create the chicken analogs. Initially, potato protein (10, 15, or 20 wt%) and gellan gum (3 or 4 wt%) were mixed to produce aqueous solutions under conditions where coacervates should form due to electrostatic attraction between the proteins and polysaccharides. This solution was then sheared to elongate and align the coacervates into fiber-like structures. Finally, the mixtures were heated (90 °C, 30 min) to induce thermal denaturation of the proteins, which stabilized the fibrous structures by gelling the proteins. The textural, rheological, and thermal properties of the chicken analogs were characterized and compared to those of real chicken. The texture and rheology of the chicken analogs became increasingly close to real chicken as the protein content of the plant-based chicken was increased from 10 to 20 wt%. Differential scanning calorimetry showed that the thermal denaturation of the potato proteins in the chicken analogs occurred over a similar temperature range as the myosin proteins in real chicken. Thermogravimetric analysis showed that the chicken analogs containing 20 wt% protein behaved the most similarly to real chicken during heating. Analysis of the appearance and microstructure of the chicken analogs showed they had aligned fibrous structures like those found in real chicken. This study suggests that soft matter physics approaches can be used for the creation of fibrous structures and the development of plant-based meat analogs.

Oleogels from mesoporous whey and potato protein based aerogel microparticles: Influence of microstructural properties on oleogelation ability

Animal-based whey protein isolate (WPI) and plant-based potato protein isolate (PPI) aerogel microparticles (particle size ∼40–77 μm) were produced via top-down wet milling of alcogels followed by supercritical–CO2–drying and used as matrices for structuring of liquid sunflower oil. pH variation (pH 3.0, 7.0, 9.0) during heat-induced gelation was used to tune aerogel microstructural properties, resulting in high specific surface areas (347–480 m2/g) and mesopore volumes (2.3–5.6 m3/g) as well as different macro-to mesoporous ratios. Oleogels oil content (70–84 wt%) and firmness (0.55–1.25 N) were related to pH during gelation, yielding firmest oleogels for aerogel templates produced at pH 9. All oleogel samples showed high physical stability, as shown by oil holding capacity (OHC) up to 95%. Minimization of macropore volume, high mesopore fractions, and high specific surface areas were found to increase OHC. Results suggest that for WPI and PPI, different aerogels microstructures induced by different gelation pH rather than protein nature, to be the driving factor affecting aerogel oleogelation ability and demonstrate the versatility of the aerogel particle-template approach in terms of protein source, thus highlighting the importance of aerogel microstructure design to fine-tune oleogel properties.

The Role of Maltodextrin Concentration in Maintaining Storage Stability of Dried Fruit Foams Texturized Using Plant Protein-Polysaccharide Blends.

Hydrocolloids are widely used in food processing because of their texture-forming abilities, which help to preserve the quality of sensitive compounds, e.g., in dried fruit foams, which have recently emerged in healthier alternative snacks. Our aim was to investigate the protective role of maltodextrin in improving the storage stability of fruit foams. This study evaluated the effect of maltodextrin concentrations on the stability of the following quality parameters: anthocyanins, ascorbic acid, color, texture, and sensory perception of dried foamed raspberry pulp during storage. This study compared three concentrations (5%, 15%, and 30% w/w) of maltodextrin in mixtures, evaluating their effect on the stability of these parameters over a 12-week storage period. The foam samples were stored at 37 °C to accelerate chemical reactions under vacuum packaging conditions which excluded oxygen. The addition of 30% maltodextrin to the raspberry pulp blend resulted in the highest retentions in all compounds tested, i.e., 74% for ascorbic acid and 87% for anthocyanins. Color and texture were similarly preserved. Adding 30% maltodextrin to the mixture did not negatively influence the acceptability of sensory perception. Maltodextrin thus represents an effective protective agent for preserving nutritional and sensory qualities for a longer storage period. Hence, using MD together with potato protein was optimal for enhancing the storage stability of fruit foam, which is important for the food industry.

Dietary inclusion of methanotrophic microbial cell-derived protein in the early postweaning period sustains growth performance and intestinal health of weaner piglets

The global demand for sustainably produced protein feeds for animal production is increasing. Methanotrophic bacteria grow on methane and convert it into microbial cell protein (MCP) that has been shown to have high nutritive value for growing pigs. The present aimed to investigate how increasing amounts of MCP in diets fed during the first 15 days after weaning affect the growth performance of piglets from weaning until day 43 postweaning. Furthermore, the effect of MCP on intestinal morphology and histopathology was assessed on day 15 after weaning. During seven consecutive weeks, approximately 480 piglets were recruited for the experiment per batch. The piglets were divided into four groups and housed in eight double pens with 60 piglets per pen. The piglets were fed one of four experimental diets with 0, 3, 6, or 10% of MCP included at the expense of fishmeal and subsequently potato protein for the first 15 days postweaning. Thereafter, all pigs were fed commercial weaner diets in two phases (days 16–30 and days 31–43) until day 43 postweaning. All diets were without medicinal zinc. Feed intake and growth were registered on double pen level during all three phases. On day 15 after weaning, 10 piglets per treatment were randomly selected, autopsied, and sampled for intestinal morphology and histopathology. Daily gain during the first 15 days postweaning tended (P = 0.09) to be affected by the inclusion of MCP in the weaning diet being lowest in the group fed 10% MCP. Treatment did not affect daily feed intake; however, Feed Conversion Ratio (FCR) was significantly affected (P = 0.003) showing the highest FCR in piglets fed 10% MCP. Growth performance was not affected by the experimental treatment during the following phases. In the small intestine, villous height tended (P = 0.09) to show a quadratic response to level of MCP in the diet with the longest villi observed after feeding 6% MCP. Dietary treatment did not affect crypt depth. The villous height to crypt depth (VC) ratio showed a quadratic response to increased dietary inclusion of MCP (P = 0.02) with piglets fed 6% MCP having the highest VC ratio. In conclusion, this study demonstrated that MCP could constitute 6% of diets as-fed (22% of total CP), at the expense of fishmeal and potato protein, for newly weaned piglets without negative effects on growth rates and FCR. The inclusion of MCP in diets for newly weaned piglets could be part of improving the sustainability of pig production.

The foaming properties of sweet potato protein hydrolysates produced by Alcalase and Ficin.

The processing of sweet potatoes generates a waste by-product rich in sweet potato protein (SPP). In this study, the effects of the concentrations of Alcalase and Ficin, hydrolysis time and pH value on the foaming properties of SPP hydrolysates (SPPHs) determined via gas sparging method were investigated. The results showed that SPPH prepared by Alcalase exhibited a significantly higher foaming expansion (the highest of 576%) than that of the SPP (462%) but displayed a weaker liquid volume stability compared with SPPH hydrolyzed by Ficin. The molecular weight of SPPH prepared by Alcalase was distributed in 10-30 kDa. A good microbiological quality of the SPPH prepared by Alcalase in pH 13 has been confirmed, and it is suitable for food application with respect to its microbiological safety profile. SPPH (pH 13) could be further safely applied in food, especially as a food additive at low concentrations to create a better organic plant-based foaming agent for the food industry. © 2023 Society of Chemical Industry.

Potato protease inhibitors, a functional food material with antioxidant and anticancer potential

Potato protease inhibitors (PPIs), as the main component of potato protein isolate, have good safety, nutrition and great market potential. The antioxidant and anticancer properties of PPIs were evaluated with cell-based biological assays. The results showed that when the concentration of PPIs was 5 mg/mL, the peroxyl radical scavenging value was (2119 ± 204) mg VCE/100 g, and the cellular antioxidant activity values were (45.83 ± 3.5) (no PBS wash) and (33.25 ± 4.4) µmol QE/100 g (PBS wash). Cells pretreated with PPIs could significantly prevent the oxidative damage induced by H2O2, inhibit the morphological changes of cells and maintain the integrity. Furthermore, PPIs had selective anti-proliferative effects on GIST882 cells (IC50 = (10.53 ± 3.87) mg/mL) and demonstrated potent inhibition of the growth, migration and invasion of cancer cells. These findings provide a scientific basis for PPIs as promising candidates for functional foods to aid in the prevention of oxidative damage and cancer.

Heat-induced gelation, rheology and stability of oil-in-water emulsions prepared with patatin-rich potato protein

The heat treatment after non-aseptic homogenization is sufficient to ensure the microbiological safety of the product, but such a sequence of processes may affect the technological suitability of protein-stabilized emulsions. In this study, we investigated the heat-induced gelation of oil-in-water emulsions prepared with patatin-rich potato proteins (EPs) and the effect of heating to 85 °C on their final properties (the appearance, rheology and stability). Low-fat and high-fat EPs of 3.2 and 30% (w/v) oil, respectively, were prepared in a two-stage high-pressure homogenizer using pressures of 50 MPa and 5 MPa in the first and second stages before heating with or without 0.1 M NaCl addition. Multi-speckle diffusing wave spectroscopy and oscillatory rheology techniques were used to monitor the molecular and macroscopic dynamics of heat-induced EPs gelation. The results showed that both, the oil content and the salt addition play a critical role in the dynamics of EPs gelation as well as in creating properties of heated and unheated emulsions, regardless of the cycles number (one or three passes through a two-stage homogenizer) of HPH pre-processing. The protein denaturation temperature in EPs ranged from 58.1 °C to 60.2 °C, but it was shifted towards lower values in the presence of salt. Heating the low-fat EPs with 3.2% (w/v) oil resulted in their transformation at 69 °C into weak gels of homogeneous structure, strong shear thinning and thixotropy and good stability against creaming. In contrast, flocculated high-fat EPs with 30% (w/v) oil formed already at 64°C64heterogeneous gels of viscoelastic solid character and poor stability due to the tendency to syneresis.

Ohmic vs. conventional heating: Influence of moderate electric fields on properties of potato protein isolate gels

The influence of moderate electric fields (MEF) on thermally induced gelation and network structures of patatin enriched potato protein (PPI) was investigated. PPI solutions with 9 wt% protein (pH 7) and 25 mM NaCl were heated from 25 to 65 °C via OH (3–24 V/cm) or conventional heating (COV) at various come-up (240 s and 1200 s) and holding times (30 s and 600 s). Self-standing gels were produced but less proteins denatured when heated via OH. Further, SDS-PAGE and GPC measurements revealed more native patatin remaining after OH treatment. Scanning electron microscopy showed OH gels to have more gap-like structures and frayed areas than COV treated gels which resulted in lower water holding capacity. On molecular scale, less hydrophobic interactions were measured within the protein network and FTIR trials showed the MEF to affect beta-sheet structures. OH gels further showed lower rigidity and higher flexibility, thus, gelling functionality was affected via OH.Industrial relevance: Ohmic heating (OH) is an advanced heating technology which has gained interest within the last decades as it is a highly energy and time efficient way to heat up foods. Additionally, as OH does not require any fossil energies, OH is considered to be a sustainable heating option for the food processing industry. During OH, electrical current is converted into heat within the food. However, it is not fully understood yet, whether OH influences the food matrix compared to conventional heating and how OH impacts certain ingredients, e.g. globular proteins and their denaturation/ gelation. This study helps to provide knowledge facilitating an implementation of OH into industry processes, serving a more sustainable food production. To evaluate the influence of OH on protein gelation, a patatin enriched potato protein was chosen as this protein offers a high protein functionality and therefore is of high interest for food industry (e.g. to be used as ingredient for plant based foods).

StOFP20 regulates tuber shape and interacts with TONNEAU1 Recruiting Motif proteins in potato

The OVATE family proteins (OFPs) are plant-specific proteins that modulate diverse aspects of plant growth and development. In tomato, OFP20 has been shown to interact with TONNEAU1 Recruiting Motif (TRM) proteins to regulate fruit shape. In this study, we demonstrated that mutation of StOFP20 caused a shift from round to oval shaped tuber in a diploid accession C151, supporting the role of StOFP20 in controlling tuber shape. Its expression reached a maximum in the tuber initiation stage and then decreased as the tuber develops. To help elucidate the mechanism of StOFP20 regulating tuber shape, 27 TONNEAU1 Recruiting Motif (TRM) proteins were identified and 23 of them were successfully amplified in C151. A yeast two-hybrid assay identified three TRM proteins interacting with StOFP20, which was confirmed by the firefly luciferase complementation in tobacco leaves. The OVATE domain was indispensable for the interactions, while necessity of the M10 motif in TRM proteins varied among interactions between StOFP20 and the three TRMs. In summary, both StOFP20 and SlOFP20 directed interactions with TRM proteins, but the interactants were not completely consistent, implying that they exert regulatory roles through partially overlapping mechanisms.

Identification and functional characterization of the SUMO system in sweet potato under salt and drought stress

Sumoylation is a crucial post-translation modification (PTM) that is the covalent attachment of SUMO molecules to the substrate catalyzed by enzyme cascade. Sumoylation is essential in almost every physiological process of plants, particularly in response to abiotic stress. However, little is known about sumoylation in sweet potato (Ipomoea batatas), the world’s seventh most important food crop. In this study, 17 sweet potato SUMO system genes have been cloned and functionally characterized. Multiple sequence alignment and phylogenetic analysis showed sweet potato SUMO system proteins had conserved domains and activity sites. IbSUMOs, IbSAE1, and IbSCE1 were localized in the cytoplasm and nucleus. E3 SUMO ligases showed nuclear or punctate localization. In vitro sumoylation assay confirmed the catalytic activity of sweet potato SUMO system components. Heterologous expression of IbSIZ1 genes in Arabidopsis atsiz1 mutant rescued the defective germination and growth phenotype. IbSCE1a/b and IbSIZ1a/b/c were salt and drought responsive genes. Heterologous expression of IbSCE1a/b/c improved the drought tolerance of Arabidopsis thaliana, while IbSIZ1a/b/c significantly enhanced the salt and drought tolerance. Our findings define that the SUMO system in sweet potato shared with conserved function but also possessed specific characterization. The resources presented here would facilitate uncovering the significance of sumoylation in sweet potato.

Effect of high intensity ultrasonic treatment on structural, rheological, and gelling properties of potato protein isolate and its co-gelation properties with egg white protein.

The study aimed to investigate the effect of high intensity ultrasonic(HIU) treatment at different times (0, 10, 20, and30 min) on the structure and gel properties of water-soluble potato protein isolate (WPPI) and to further investigate the improvement of gel properties of ultrasonicated WPPI (UWPPI) by the addition of egg white protein (EWP). HIU reduced theparticle size of WPPI, whose structure became loose and disordered, which improved gelling properties of UWPPI. Fourier transform infrared results indicated that α-helix content decreased, whereas the proportion of irregular curl increased with the increase in ultrasonication time (0-20 min), indicating that the initially ordered structure of UWPPI became disordered. AfterHIUtreatment, thefree sulfhydryl groups of UWPPI and surface hydrophobicity decreased and fluorescence intensity increased. Theseresultsdemonstrated that the HIUloosenedthestructure of UWPPI, exposing more chromogenic groups while embedding more hydrophilic groups. After thermal induction, UWPPI gel hardness increased and exhibited excellent water holding capacity. After the addition of EWP, rheological properties stabilized, and thehardness of UWPPI-EWP gels increased significantly, forming internally structured protein gels with a tightly ordered structure and increased brightness. Thus, HIU changed the structure and gelling properties of WPPI, and the addition of EWP further enhanced the performance of hybrid protein gels. PRACTICAL APPLICATION: High intensity ultrasonic changed the structure of water-soluble potato protein isolate (WPPI) and improved the properties of WPPI gels. The addition of egg white protein significantly improved the quality of mixed protein gels which showed great potential industrial value.

The properties of potato gluten-free doughs: comparative and combined effects of propylene glycol alginate and hydroxypropyl methyl cellulose or flaxseed gum

Abstract Different methods are often used to make gluten-free (GF) bread to get better bread characteristics. To explore the effects of emulsifiers and hydrocolloids on the characteristics of GF dough, different esterification levels of propylene glycol alginate (PGA), hydroxypropyl methyl cellulose (HPMC), flaxseed gum with (FG) different molecular weight, and the binary blends of HPMC/PGA and FG/PGA were added to GF dough, made with potato starch and potato protein in a ratio of 6:4. The results showed that the potato GF dough with FG and FG/PGA obtained a higher viscoelasticity than the other doughs. HPMC and FG promoted to the formation of network structure, but the network structure formed by PGA and their combination was more developed. It was found that all PGA, HPMC, FG and their combination could improve the softness of GF breads. The results provided a basis for optimizing the quality of potato GF bread.

Impact of process conditions and type of protein on conjugate formation with pectin by vacuum drying

Plant proteins exhibit low solubility and functionality, limiting their use as emulsifiers. Maillard reaction-based conjugation with polysaccharides, e.g. pectin, is a strategy to improve their functionality. The commonly applied batch process involves economically unviable freeze-drying as a pre-treatment. Vacuum drying was therefore investigated as a novel approach combining the drying process and conjugate formation.First, the process parameters (time and temperature) were altered to determine the optimum conditions for conjugation between potato protein and high methoxylated pectin. Then, the conjugation between the pectin and various plant proteins (soy, pea, rapeseed) was tested to assess the impact of protein type. Conjugate samples were analysed by dry matter, decrease in free amino groups, browning index and molecular weight. Emulsifying properties were evaluated by oil droplet size and emulsion stability. Process parameters of 100 °C and 3 h were identified to favour conjugation. Corresponding potato protein conjugates had high molecular weight and improved emulsion stability at the pI of the protein. Soy protein conjugates showed the highest decrease in free amino groups and enhanced emulsion stability with prevented coalescence. Rapeseed protein conjugates exhibited the most stable emulsions with narrow oil droplet size distribution but were hampered by their inherent colouration.The results confirm that all plant proteins can be used for conjugation with pectin and the obtained conjugates are suitable as emulsifiers for food systems. However, differences in the amino acids content, chemical structure, and overall composition of plant proteins affect conjugation and must be considered in process design.

N-Linked Glycoproteome Analysis of Diosorea alata Tuber Shows Atypical Glycosylation and Indicates Central Role of Glycosylated Proteins in Tuber Maturation.

Glycosylation is an important post translational modification in plants. First analysis of N-linked glycosylated proteins of Dioscorea alata using Concanavalin A lectin affinity chromatography enrichment coupled with label free quantification is presented. In total, 114 enriched glycoproteins were detected. Signal P and sub-cellular localization showed 42.2% of proteins to be secretory. These included peroxidases, endochitinases, calreticulin, calnexin, thaumatins and lipid transfer proteins. Gene Ontology and MapMan analysis predicted the enriched glycoproteins to be involved in processes essential for tuber maturation namely: signal transduction, lignification, protein trafficking, endoplasmic reticulum quality control and cell wall remodeling. This was supported by biochemical validation of the essential glycoproteins. Interestingly, out of the two dioscorin isoforms, Dio B was the only N-glycosylated form. In silico analysis showed O-glycosylation sites in the other form, Dio A suggesting its similarity with sporamin, the storage protein of sweet potato. Absence of signal peptide in Dio B and the presence of non-canonical motif hints towards its atypical glycosylation. The analysis revealed that N-glycosylation of Dio B isoform maintains the activities associated with Dioscorin at maturity and provides an overview of protein N-glycosylation, enriching the glycoproteome database of plants especially tubers.

Physical and oxidative stability of fish oil-in-water emulsions stabilized with emulsifier peptides derived from seaweed, methanotrophic bacteria and potato proteins

This study investigated the emulsifying and antioxidant activity of 10 peptides derived from seaweed, methanotrophic bacteria, and potatoes, which were identified as emulsifiers using quantitative proteomics and predictive bioinformatics. The factors (e.g., interfacial properties, secondary structure, net charge) behind the dual-functionality of peptides were characterized and related to peptides’ ability to provide physical and oxidative stability in 5 % fish oil-in-water emulsions during 10 days of storage. The secondary structure of some of the peptides changed from highly disordered to more α-helical (GIIPATILEFLEGQLQEVDNNKDAR and GIIPGTILEFLEGQLQK) or β-strand (VGFACSGSAQTYLSFEGDNTGRGEEEVAI, ELQVSARVTLEIEL, KVKINETVEIKGKFHV, RSPQKKESDMMKATKFAVVLMAAGLTVGCA) structures when adsorbed at the oil-water interface in comparison to aqueous solution. The physical stability analyses confirmed that three seaweed peptides (IDSSFDSLPTDVVRVANSSCDAVE, VGFACSGSAQTYLSFEGDNTGRGEEEVAI, and ELQVSARVTLEIEL), one of the methanotrophic bacteria peptides (KVKINETVEIKGKFHV) and two of the potato peptides (GIIPATILEFLEGQLQEVDNNKDAR and GIKGIIPAIILEFLEGQLQEVDNNKDAR) can indeed produce physically stable emulsions. The predicted emulsifier peptide embedded in methanotrophic bacteria protein (KVKINETVEIKGKFHV) outperformed all the samples in its ability to retard lipid oxidation in emulsions. This was evident as this sample had the lowest hydroperoxides formation (peroxide value < 10 meq O2/ kg oil), tocopherols consumption, and volatile compound concentration, especially for t,t-2,4-heptadienal (14 ng/g sample) and 2-ethyl-furan (no formation). Non-enzymatic browning, which may indicate advanced stages of oxidation, occurred in all emulsions except for those stabilized with KVKINETVEIKGKFHV and sodium caseinate. Even though the positively charged peptides yielded better oxidative stability compared to negatively charged ones, there are several other factors (i.e., length, structure, charge, ability to decrease oil-water interfacial tension) affecting the physical and oxidative stability of emulsions. Therefore, it must be kept in mind that it is the collective action of these factors that ultimately define the functionality of peptides. In its entirety, KVKINETVEIKGKFHV proved to be highly effective in its technological functions as an emulsifier and antioxidant.

The alleviative effect of sweet potato protein hydrolysates on the quality deterioration of frozen dough bread in comparison to trehalose

The effects of different sweet potato protein hydrolysates (SPPH) concentrations (1, 2, 3, g/100 g) on the frozen dough bread in comparison to trehalose (3 g/100 g) were evaluated. The results showed that the addition of SPPH at all examined levels can retard the quality deterioration of frozen dough and a greater amount of SPPH showed better effect. During the frozen storage, the addition of 3 g SPPH showed an increase in yeast viability from 43.01% to 79.03%, and a decrease in freezable water content, tan δ and free sulfhydryl groups from 57. 21%, 0.74 and 5.74 μmol/g to 47.72%, 0.69 and 3.96 μmol/g, respectively. After frozen storage for 56 days, compared with the control, the addition of SPPH at 3 g significantly increased the specific volume of bread from 3.15 mL/g to 3.97 mL/g, and the porosity and mean area of pore increased from 23.18%, 0.26–32.55%, 0.43, respectively, authenticated by the observations of SEM, binary and representative images. Furthermore, the hardness significantly decreased from 1224.90 g to 839.93 g. These findings suggested that SPPH can be potently employed as a natural food-derived cryoprotectant agent for improving the quality and nutrition of frozen dough.

Insecticidal and Potato Growth Stimulation Activity of Bacillus thuringiensis kurstaki HD-1

Bacillus thuringiensis (Bt) produces Cry toxins against pest insects. Cry proteins are conformed by domains related to pore formation and recognition of protein receptors. Plant-induced systemic resistance (ISR) is triggered due to pest attack, it could be activated by Bacillus sp. Tecia solanivora (Ts) is a potato pest, susceptible to Cry1Ac and Cry1B proteins. This paper indicates the endorsement of Bt kurstaki HD-1 (BtkHD1) in relation to Ts control (Cry1Ac and Cry1B proteins), potato growth promotion, and plant ISR due to pests related to the BtkHD1-potato system. To ensure that ongoing quality control of BtkHD1 was maintained, crystal synthesis (microscopy), cry1 genes presence, and Cry protein production were checked. Bioassays Ts larvae and potato plantlets and an in silico analysis of the hybrid Cry1Ac-Cry1Ba protein and potato ISR related to the BtkHD1 infl uence were performed. Bioassay on Ts larvae shows an LC50 of 536 ng/cm2 of diet. A potato growth promotion assay revealed the effect of BtkHD1 on the length and dry weight of stems. The prospective analysis took into account relevant factors affecting the biological function of the hybrid protein focused on domain II. In silico identification of 15 BtkHD1 proteins and 68 potato proteins related to plant ISR due to pests was completed. This project serves to validation of toxicity on Ts larvae and potato growth effect based on BtkHD1, including a forward analysis of the hybrid Cry1Ac1-Cry1Ba1, and proteins associated with this strain and potato for eliciting plant ISR due to pests.

Towards maximum value creation from potato protein liquor: volatile fatty acids production from fungal cultivation effluent

The cornerstones of an efficient circular waste management strategy aiming for enhanced resource efficiency are maximizing organic waste valorization and improving residual conversion to biochemicals. In this regard, this study focuses on the production of volatile fatty acids (VFAs) from the effluent of fungi biomass cultivation on low-grade residues from the potato starch industry with batch and semi-continuous membrane bioreactors (MBRs) containing the effluent of already fermented potato protein liquor (FPPL) inoculated with chicken and cow manure. The effect of pH in the batch experiments on the production and yield of VFAs during acidogenic digestion was evaluated. Rapid generation of VFAs at a concentration of up to 11.8 g/L could be successfully achieved in the MBR. Under the optimal conditions, a high yield of 0.65 g VFAs/g VSfed was obtained for the organic loading rate (OLR) of 1 g VS/L/d using FPPL substrate and chicken manure as inoculum. The results show that the application of sequential multi-step bioconversion of potato starch industry residues has the potential to increase the variety of value-added products generated from a single organic residue while enhancing nutrient recovery capacity.

Potato protein tyrosine phosphatase StPTP1a is activated by StMKK1 to negatively regulate plant immunity.

Phytophthora infestans causes severe losses in potato production. The MAPK kinase StMKK1 was previously found to negatively regulate potato immunity to P. infestans. Our results showed that StMKK1 interacts with a protein tyrosine phosphatase, referred to as StPTP1a, and StMKK1 directly phosphorylates StPTP1a at residues Ser-99, Tyr-223 and Thr-290. StPTP1a is a functional phosphatase and the phosphorylation of StPTP1a at these three residues enhances its stability and catalytic activity. StPTP1a negatively regulates potato immunity and represses SA-related gene expression. Furthermore, StPTP1a interacts with, and dephosphorylates, the StMKK1 downstream signalling targets StMPK4 and -7 at their Tyr-203 residue resulting in the repression of salicylic acid (SA)-related immunity. Silencing of NbPTP1a + NbMPK4 or NbPTP1a + NbMPK7 abolished the plant immunity to P. infestans caused by NbPTP1a silencing, indicating that PTP1a functions upstream of NbMPK4 and NbMPK7. StMKK1 requires StPTP1a to negatively regulate SA-related immunity and StPTP1a is phosphorylated and stabilized during immune activation to promote the de-phosphorylation of StMPK4 and -7. Our results reveal that potato StMKK1 activates and stabilizes the tyrosine phosphatase StPTP1a that in its turn de-phosphorylates StMPK4 and -7, thereby repressing plant SA-related immunity.