Comparison of Structural and Functional Properties of Wheat Starch Under Different Soil Drought Conditions

Changes of crystalline structure and physicochemical properties of Pueraria lobata var. thomsonii starch under water deficit

Crystal type is an important physicochemical property of starch. However, it is currently unclear whether changes in crystal type affect other properties of starch. This study discovered that water deficit resulted in an increase in small starch granules and transparency in Pueraria lobata var. thomsonii, while causing a decrease in amylose content and swelling power. Additionally, the crystal type of P. Thomsonii starch changed from CB-type to CA-type under water deficit, without significantly altering the short-range ordered structure and chain length distribution of starch. This transformation in crystal type led to peak splitting in the DSC heat flow curve of starch, alterations in gelatinization behavior, and an increase in resistant starch content. These changes in crystalline structure and physicochemical properties of starch granules are considered as adaptive strategies employed by P. Thomsonii to cope with water deficit.

Strategies for starch customization: Agricultural modification

Raw starch is commonly modified to enhance its functionality for industrial applications. There is increasing demand for 'green' modified starches from both end-consumers and producers. It is well known that environmental conditions are key factors that determine plant growth and yield. An increasing number of studies suggest growth conditions can expand affect starch structure and functionality. In this review, we summarized how water, heat, high nitrogen, salinity, shading, CO2 stress affect starch biosynthesis and physicochemical properties. We define these treatments as a fifth type of starch modification method - agricultural modification - in addition to chemical, physical, enzymatic and genetic methods. In general, water stress decreases peak viscosity and gelatinization enthalpy of starch, and high temperature stress increases starch gelatinization enthalpy and temperature. High nitrogen increases total starch content and regulates starch viscosity. Salinity stress mainly regulates starch and amylose content, both of which are genotype-dependent. Shading stress and CO2 stress can both increase starch granule size, but these have different effects on amylose content and amylopectin structure. Compared with other modification methods, agricultural modification has the advantage of operating at a large scale and a low cost and can help meet the ever-rising market of clean-label foods and ingredients.

Variation in quality of grains used in malting and brewing

Cereal grains have been domesticated largely from food grains to feed and malting grains. Barley (Hordeum vulgare L.) remains unparalleled in its success as a primary brewing grain. However, there is renewed interest in "alternative" grains for brewing (and distilling) due to attention being placed on flavor, quality, and health (i.e., gluten issues) aspects that they may offer. This review covers basic and general information on "alternative grains" for malting and brewing, as well as an in-depth look at several major biochemical aspects of these grains including starch, protein, polyphenols, and lipids. These traits are described in terms of their effects on processing and flavor, as well as the prospects for improvement through breeding. These aspects have been studied extensively in barley, but little is known about the functional properties in other crops for malting and brewing. In addition, the complex nature of malting and brewing produces a large number of brewing targets but requires extensive processing, laboratory analysis, and accompanying sensory analysis. However, if a better understanding of the potential of alternative crops that can be used in malting and brewing is needed, then significantly more research is required.

A new insight into the biosynthesis, structure, and functionality of waxy maize starch under drought stress

BACKGROUND

Drought stress (DS) is the main abiotic stress that maize suffers during its whole growth period, and maize is also sensitive to DS. It had been demonstrated that DS could improve the quality of normal maize starch. However, waxy maize, which has special properties, has not been explored in depth, which limits the breeding and cultivation of waxy maize varieties and the application of waxy maize starch. Therefore, in this study, we investigated the effects of DS on the biosynthesis, structure, and functionality of waxy maize starch.

RESULTS

The results showed that DS decreased the expression level of SSIIb, SSIIIa, GBSSIIa, SBEI, SBEIIb, ISAII, and PUL, but increased the expression level of SSI and SBEIIa. DS did not change the average chain length of amylopectin, while increased the relative content of fa chains (RC_fa ) and decreased the RC_fb1 and RC_fb3 . Furthermore, DS decreased the amylose content, amorphous lamellar distance d_a , semi-crystalline repeat distance, and average particle size, whereas it increased the relative crystallinity, crystalline distance d_c , the content of rapidly digested starch in the uncooked system and resistant starch content in both the uncooked and cooked system.

CONCLUSIONS

For waxy maize, DS could raise the relative expression level of SSI and SBEIIa, thus increasing RC_fa . The larger number of RC_fa could create steric hindrance, which can lead to producing more resistant starch in waxy maize starch. © 2023 Society of Chemical Industry.

Long-Term Soil Drought Limits Starch Accumulation by Altering Sucrose Transport and Starch Synthesis in Sweet Potato Tuberous Root

In this study, the influences of long-term soil drought with three levels [soil-relative water content (SRWC) (75 ± 5)%, as the control; SRWC (55 ± 5)%, mild drought; SRWC (45 ± 5)%, severe drought] were investigated on sucrose-starch metabolism in sweet potato tuberous roots (TRs) by pot experiment. Compared to the control, drought stress increased soluble sugar and sucrose content by 4-60% and 9-75%, respectively, but reduced starch accumulation by 30-66% through decreasing the starch accumulate rate in TRs. In the drought-treated TRs, the inhibition of sucrose decomposition was attributed to the reduced activities of acid invertase (AI) and alkaline invertase (AKI) and the IbA-INV3 expression, rather than sucrose synthase (SuSy), consequently leading to the increased sucrose content in TRs. In addition, starch synthesis was inhibited mainly by reducing ADP-glucose pyrophosphorylase (AGPase), granular starch synthase (GBSS) and starch branching enzyme (SBE) activities in TRs under drought stress, and AGPase was the rate-limiting enzyme. Furthermore, soil drought remarkably up-regulated the IbSWEET11, IbSWEET605, and IbSUT4 expressions in Jishu 26 TRs, while it down-regulated or had no significant differences in Xushu 32 and Ningzishu 1 TRs. These results suggested that the sucrose-loading capability in Jishu 26 TRs were stronger than that in Xushu 32 and Ningzishu 1 TRs. Moreover, IbA-INV3, IbAGPS1, IbAGPS2, IbGBSSI and IbSBEII play important roles in different drought-tolerant cultivars under drought stress.

Effects of the duration of post-silking drought on the starch physicochemical properties of waxy maize

BACKGROUND

Drought is a major abiotic stress that affects the physicochemical properties of cereal starch. However, quantitative information on the effects of drought duration on the starch quality of waxy maize, a special maize-type starch composed of nearly pure amylopectin, has been lacking. The effects of post-silking drought duration 1-10 (DS10), 1-20 (DS20), and 1-30 (DS30) days after pollination on the physicochemical properties of starch were assessed from 2019 to 2020 using two waxy maize hybrids as materials.

RESULTS

With extending drought duration, the starch granule size and average amylopectin chain length of Jingkenuo2000 (JKN2000) gradually increased, with those of Suyunuo5 (SYN5) being the highest for DS20, followed by DS30. All drought durations decreased the degree of branching of both hybrids, with the lowest value obtained for DS30 and DS20 in JKN2000 and SYN5, respectively. Relative crystallinity increased for DS30 in both hybrids but its responses for DS10 and DS20 differed. Pasting viscosities and gelatinization enthalpy were decreased and retrogradation percentage was increased by drought stress. The lowest pasting viscosities were observed for DS30, and the highest retrogradation percentage was found for DS10 in general.

CONCLUSION

Post-silking drought led to the pasting and retrogradation properties deteriorating, with decreased pasting viscosities and increased retrogradation percentage. The decrease in viscosity was caused by enlarged granules. Meanwhile, the increased proportion of amylopectin chains with a degree of polymerization of 25-36 resulted in lower viscosity and higher retrogradation. © 2022 Society of Chemical Industry.

Fertilization time of slow-release fertilizer affects the physicochemical properties of starch from spring-sown waxy maize

BACKGROUND

Slow-release fertilizer is widely used in cereal crop production because it is ecofriendly and laborsaving. Effects of different application stages (zero-, three-, and six-leaf stages, denoted as SN0, SN3, and SN6, respectively) of slow-release (N/P₂ O₅ /K₂ O = 225/75/75 kg ha^-1 ) fertilizer on physicochemical properties of starch from spring-sown waxy maize were investigated in 2018 and 2019. Application of traditional fertilizer (NCK, compound fertilizer; N/P₂ O₅ /K₂ O = 75/75/75 kg ha^-1 ) at sowing time and urea (N = 150 kg ha^-1 ) at six-leaf stage was designated as the control.

RESULTS

In comparison to the NCK, SN0 reduced grain starch content by 4.9%. Meanwhile, SN3 and SN6 did not affect this parameter. Nevertheless, all treatments, particularly SN6, increased average starch granule size. The slow-release fertilizer reduced proportion of chains with degree of polymerization (DP) > 24. Relative to NCK, SN6 increased starch crystallinity in both years, whereas SN0 and SN3 increased it in 2018 but reduced it in 2019. SN0 reduced peak, trough, and final viscosities, whereas SN3 and SN6 produced similar starch viscosities to those produced by NCK. No fertilizer mode affected gelatinization parameters, but SN6 produced a low retrogradation percentage. In comparison to data for 2018, starch produced in 2019 showed a small granule size, and a high proportion of short amylopectin chains. These properties endowed starch with high viscosity and low retrogradation percentage.

CONCLUSION

In spring-sown waxy maize production, applying slow-release fertilizer at the six-leaf stage produced starch with high viscosity and low retrogradation tendency by enlarging granule size, increasing crystallinity, and reducing the proportion of long chains. © 2021 Society of Chemical Industry.

Yield, Grain Quality, and Starch Physicochemical Properties of 2 Elite Thai Rice Cultivars Grown under Varying Production Systems and Soil Characteristics

Rice production systems and soil characteristics play a crucial role in determining its yield and grain quality. Two elite Thai rice cultivars, namely, KDML105 and RD6, were cultivated in two production systems with distinct soil characteristics, including net-house pot production and open-field production. Under open-field system, KDML105 and RD6 had greater panicle number, total grain weight, 100-grain weight, grain size, and dimension than those grown in the net-house. The amounts of reducing sugar and long amylopectin branch chains (DP 25–36) of the RD6 grains along with the amounts of long branch chains (DP 25–36 and DP ≥ 37), C-type starch granules, and average chain length of the KDML105 were substantially enhanced by the open-field cultivation. Contrastingly, the relative crystallinity of RD6 starch and the amounts of short branch chains (DP 6–12 and DP 13–24), B- and A-type granules, and median granule size of KDML105 starch were significantly suppressed. Consequently, the open-field-grown RD6 starch displayed significant changes in its gelatinization and retrogradation properties, whereas, certain retrogradation parameters and peak viscosity (PV) of KDML105 starches were differentially affected by the distinct cultivating conditions. This study demonstrated the influences of production systems and soil characteristics on the physicochemical properties of rice starches.

Wheat Biocomposite Extraction, Structure, Properties and Characterization: A Review

Biocomposite materials create a huge opportunity for a healthy and safe environment by replacing artificial plastic and materials with natural ingredients in a variety of applications. Furniture, construction materials, insulation, and packaging, as well as medical devices, can all benefit from biocomposite materials. Wheat is one of the world’s most widely cultivated crops. Due to its mechanical and physical properties, wheat starch, gluten, and fiber are vital in the biopolymer industry. Glycerol as a plasticizer considerably increased the elongation and water vapor permeability of wheat films. Wheat fiber developed mechanical and thermal properties as a result of various matrices; wheat gluten is water insoluble, elastic, non-toxic, and biodegradable, making it useful in biocomposite materials. This study looked at the feasibility of using wheat plant components such as wheat, gluten, and fiber in the biocomposite material industry.

Improved response of triploid citrus varieties to water deficit is related to anatomical and cytological properties

Polyploidy plays a major role in citrus plant breeding to improve the adaptation of polyploid rootstocks as well as scions to adverse conditions and to enhance agronomic characteristics. In Citrus breeding programs, triploidy could be a useful tool to react to environmental issues and consumer demands because the produced fruits are seedless. In this study, we compared the physiological, biochemical, morphological, and ultrastructural responses to water deficit of triploid and diploid citrus varieties obtained from 'Fortune' mandarin and 'Ellendale' tangor hybridization. One diploid clementine tree was included and used as a reference. All studied scions were grafted on C-35 citrange rootstock. Triploidy decreased stomatal density and increased stomata size. The number of chloroplasts increased in 3x varieties. These cytological properties may explain the greater photosynthetic capacity (P_net, g_s, F_v/F_m) and enhanced water-holding capacity (RWC, proline). In addition, reduced degradation of ultrastructural organelles (chloroplasts and mitochondria) and thylakoids accompanied by less photosynthetic activity and low oxidative damages were found in 3x varieties. Triploid varieties, especially T40-3x, had a better ability to limit water loss and dissipate excess energy (NPQ) to protect photosystems. Higher starch reserves in 3x varieties suggest a better carbon and energy supply and increases in plastoglobuli size suggest less oxidative damage (H₂O₂, MDA), especially in T40-3x, and preservation of photosynthetic apparatus. Taken together, our results suggest that desirable cytological and ultrastructural traits induced by triploidy improve water stress response and could be a useful stress marker during environmental constraints.

Biochemical and synergistic properties of a novel alpha-amylase from Chinese nong-flavor Daqu

Background

Daqu is the most important fermentation starter for Chinese liquor, with large number of microbes and enzymes being openly enriched in the Daqu system over thousands of years. However, only a few enzymes have been analyzed with crude protein for total liquefying power and saccharifying power of Daqu. Therefore, the complex enzymatic system present in Daqu has not been completely characterized. Moreover, their pivotal and complicated functions in Daqu are completely unknown.

Results

In this study, a novel α-amylase NFAmy13B, from GH13_5 subfamily (according to the Carbohydrate-Active enZYmes Database, CAZy) was successfully heterologous expressed by Escherichia coli from Chinese Nong-flavor (NF) Daqu. It exhibited high stability ranging from pH 5.5 to 12.5, and higher specific activity, compared to other GH13_5 fungal α-amylases. Moreover, NFAmy13B did not show activity loss and retained 96% residual activity after pre-incubation at pH 11 for 21 h and pH 12 for 10 h, respectively. Additionally, 1.25 mM Ca²⁺ significantly improved its thermostability. NFAmy13B showed a synergistic effect on degrading wheat starch with NFAmy13A (GH13_1), another α-amylase from Daqu. Both enzymes could cleave maltotetraose and maltopentaose in same degradation pattern, and only NFAmy13A could efficiently degrade maltotriose. Moreover, NFAmy13B showed higher catalytic efficiency on long-chain starch, while NFAmy13A had higher catalytic efficiency on short-chain maltooligosaccharides. Their different catalytic efficiencies on starch and maltooligosaccharides may be caused by their discrepant substrate-binding region.

Conclusions

This study mined a novel GH13_5 fungal α-amylase (NFAmy13B) with outstanding alkali resistance from Nong-flavor (NF) Daqu. Furthermore, its synergistic effect with NFAmy13A (GH13_1) on hydrolyzing wheat starch was confirmed, and their possible contribution in NF Daqu was also speculated. Thus, we not only provide a candidate α-amylase for industry, but also a useful strategy for further studying the interactions in the complex enzyme system of Daqu.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12934-021-01571-w.

A Mobile NMR Sensor and Relaxometric Method to Non-destructively Monitor Water and Dry Matter Content in Plants

Water content (WC) and dry matter content (DMC) are some of the most basic parameters to describe plant growth and yield, but are exceptionally difficult to measure non-invasively. Nuclear Magnetic Resonance (NMR) relaxometry may fill this methodological gap. It allows non-invasive detection of protons in liquids and solids, and on the basis of these measures, can be used to quantify liquid and dry matter contents of seeds and plants. Unfortunately, most existing NMR relaxometers are large, unwieldy and not suitable to measure intact plants or to be used under field conditions. In addition, currently the appropriate NMR relaxometric methods are poorly suited for non-expert use. We here present a novel approach to overcome these drawbacks. We demonstrate that a basic NMR relaxometer with the capability to accept intact plants, in combination with straightforward NMR and data processing methods, can be used as an NMR plant sensor to continuously, quantitatively and non-invasively monitor changes in WC and DMC. This can be done in vivo, in situ, and with high temporal resolution. The method is validated by showing that measured liquid and solid proton densities accurately reflect WC and DMC of reference samples. The NMR plant sensor is demonstrated in an experimental context by monitoring WC of rice leaves under osmotic stress, and by measuring the dynamics of water and dry matter accumulation during seed filling in a developing wheat ear. It is further demonstrated how the method can be used to estimate leaf water potential on the basis of changes in leaf water content.

Application of Exogenous Phytohormones at Silking Stage Improve Grain Quality under Post-Silking Drought Stress in Waxy Maize

The application of exogenous plant growth regulator can improve plant resistance to drought stress. The effects of application of exogenous cytokinin (CTK), brassinolide (BR), or gibberellic acid (GA) at the silking time on the grain quality of two waxy maize hybrids under drought stress at grain formation stage were studied. Grain weight of both hybrids was unaffected by exogenous phytohormones under control conditions but increased under drought conditions with the application of BR. The grain starch content in response to drought varied with hybrid and phytohormone. Starch granule size and protein content in grains were increased by drought under all conditions, but various phytohormones exerted different forms of influence. The starch λ_max in Yunuo7 was unaffected by single or interaction of phytohormones and water deficit, λ_max in Jingkenuo2000 with BR was unaffected but with CTK or GA increased by drought. Relative crystallinity was reduced by drought without the application of phytohormone, but with phytohormones in response to drought it was different. Flour peak viscosity was reduced by drought. The value was increased with BR spraying under control and drought conditions. Retrogradation percentage under drought conditions was unaffected by exogenous phytohormones in Jingkenuo2000. In Yunuo7, retrogradation percentage was unaffected by BR but reduced by CTK and GA. In conclusion, spraying phytohormones at the silking stage can affect grain weight and starch quality, grains with a sticky taste can be improved by applying BR, and grains with low retrograde tendency can be produced by applying CTK.

Pre-harvest glyphosate application and effects on wheat starch chemistry: Analysis from application to harvest

The objective of this study was to determine if the pre-harvest glyphosate application time affects the chemistry of wheat starch. Glyphosate was sprayed at the ripe stage (recommended) and the soft dough stage (early application) of hard red spring wheat. Wheat kernel samples were collected before application and every 3 days until harvest, after which different starch characteristics were analyzed. The results indicate that glyphosate timing does not impact the spatial distribution or morphology of starch granules, as well as the percentage or molecular weight of amylose and amylopectin. However, thermal characteristics of wheat starch, especially when glyphosate was applied at the soft dough stage, showed significant differences. A decrease in the average amylopectin chain length and differences in the proportion of short-, medium-, and long-chain amylopectin was also observed. Overall, this study shows that the pre-harvest application of glyphosate can affect wheat starch chemistry, especially if applied earlier than recommended. PRACTICAL APPLICATIONS: Glyphosate is the most commonly used herbicide in the world, and it is sometimes used pre-harvest during wheat cultivation. The recommended time of application is 7 days prior to harvest when the crops are in the ripe stage of physiological maturity. However, some crops may not be at this stage during application due to non-uniform maturation in the field. The goal of this work was to determine the effect of glyphosate application time (recommended/ripe stage vs. early/soft dough stage) on wheat starch chemistry. The results show that the starch chain length characteristics and thermal behavior are impacted, especially if applied early. Thus, this study shows the importance of timely application to avoid effects on starch chemical properties, which in return could impact starch functionality in food systems. This information is critical in the field of agriculture and to our knowledge this study is one of the first in this area.

Preharvest Glyphosate Application during Wheat Cultivation: Effects on Wheat Starch Physicochemical Properties

Due to nonuniform maturation, some plants may not be at the recommended stage of maturity when preharvest glyphosate is applied. The objective of this study was to determine how preharvest glyphosate timing affects wheat starch physicochemical properties. Two wheat cultivars were grown in three locations, and glyphosate was applied at the soft dough stage (early application) and the ripe stage (commercial standard). Upon harvest, starch chemical characteristics were studied. The proportion of B-type starch granules was lower in treated samples, although the starch molecular weight was not affected. Rapidly digestible starch content was highest when glyphosate was applied at the ripe stage, and lowest in the control, and vice versa for slowly digestible starch. Additionally, flour pasting viscosity was significantly higher in samples treated at the soft dough stage. Overall, the effects on wheat starch physicochemical characteristics were more pronounced when glyphosate was applied at the soft dough stage of maturity.

Activities of starch synthetic enzymes and contents of endogenous hormones in waxy maize grains subjected to post-silking water deficit

Rainfed maize in Southern China and frequently suffer water deficit at later plant growth periods. A pot trial in 2014–2015 was conducted to study the effects of drought stress (the relative soil moisture contents are 70–80% and 50–60% under control and water deficit conditions, respectively) after pollination on grain filling and starch accumulation, activities of starch synthetic enzymes, and contents of indole-3-acetic acid (IAA) and abscisic acid (ABA), with Suyunuo5 as test material. The grain fresh weight, volume, and dry weight were not affected by drought before 10 days after pollination but were restricted thereafter. The reduction at maturity was reduced by 33.3%, 40.0%, and 32.3% in 2014 and by 21.7%, 24.3%, and 18.3% in 2015. The grain filling rate was suppressed by water deficit, whereas grain moisture and starch content were slightly affected. The starch accumulation was decreased by 33.5% and 20.0% at maturity in 2014 and 2015, respectively. The activities of starch synthetic enzymes (sucrose phosphate synthase, sucrose synthase, ADP-glucose pyrophosphorylase, soluble starch synthase, and starch branching enzyme) were downregulated by post-silking drought. The ABA content was increased, whereas IAA content was decreased when plants suffered water deficit during grain filling. In conclusion, post-silking water deficit increased ABA content, decreased IAA content, and weakened the activities of starch synthetic enzymes, which suppressed grain development and ultimately reduced grain weight.

Mineral Composition and Baking Value of the Winter Wheat Grain under Varied Environmental and Agronomic Conditions

The mineral composition of cereal crops, the technological value of grain and flour, as well as bread quality are affected by the genotype, environment, and agronomic management practices. The aim of the research has been to investigate the effect of the environment and agronomic factors on the mineral composition and baking value of winter wheat grain. Opal cultivar grain of the genetically determined prime-quality wheat was obtained in a two-year field experiment (varied soil and weather). The agronomic management practices included tillage (conventional moldboard-plow, reduced ploughless, and strip-till) and nitrogen fertilisation rate (100 kg·N·ha−1, 200 kg·N·ha−1). In the grain samples, the content of macronutrients was assayed: P, K, Mg, Ca, and Na, total protein, and wet gluten as well as sedimentation value. The colour and the water absorption of flour and its content of protein and ash were determined. Laboratory baking was performed. It was found that the content of protein and gluten in grain, sedimentation value, bread volume, and weight changed depending on the environmental conditions and research years. Tillage and nitrogen rate, despite an effect on the properties of grain and flour, did not differentiate, however, the bread quality. The environmental conditions and agronomic management practices did not have a significant effect on the content of mineral nutrients in grain, except for calcium. The biofortification with mineral nutrients in prime-quality winter wheat cultivar grain by selecting the environmental and agronomic conditions seems more difficult than increasing the content of organic compounds and enhancement of flour and bread parameters.

Directly mining a fungal thermostable α-amylase from Chinese Nong-flavor liquor starter

BACKGROUND

Chinese Nong-flavor (NF) liquor is continuously and stably produced by solid-state fermentation technology for 1000 years, resulting in enrichment of special microbial community and enzymes system in its starter. Based on traditional culture-dependent methods, these functional enzymes are hardly obtained. According to our previous metatranscriptomic analysis, which identifies plenty of thermostable carbohydrate-active enzymes in NF liquor starter, the aim of this study is to provide a direct and efficient way to mine these thermostable enzymes.

RESULTS

In present study, an alpha-amylase (NFAmy13A) gene, which showed the highest expression level of enzymes in starch degradation at high temperature stage (62 °C), was directly obtained by functional metatranscriptomics from Chinese Nong-flavor liquor starter and expressed in Pichia pastoris. NFAmy13A had a typical signal peptide and shared the highest sequence identity of 64% with α-amylase from Aspergillus niger. The recombinant enzyme of NFAmy13A showed an optimal pH at 5.0-5.5 and optimal temperature at 60 °C. NFAmy13A was activated and stabilized by Ca²⁺, and its half-lives at 60 and 70 °C were improved significantly from 1.5 and 0.4 h to 16 and 0.7 h, respectively, in the presence of 10 mM CaCl₂. Meanwhile, Hg²⁺, Co²⁺ and SDS largely inhibited its activity. NFAmy13A showed the maximum activity on amylopectin, followed by various starches, amylose, glycogen, and pullulan, and its specificity activity on amylopectin was 200.4 U/mg. Moreover, this α-amylase efficiently hydrolyzed starches (from corn, wheat, and potato) at high concentrations up to 15 mg/ml.

CONCLUSIONS

This study provides a direct way to mine active enzymes from man-made environment of NF liquor starter, by which a fungal thermostable α-amylase (NFAmy13A) is successfully obtained. The good characteristics of NFAmy13A in degrading starch at high temperature are consistent with its pivotal role in solid-state fermentation of NF liquor brewing. This work would stimulate mining more enzymes from NF liquor starter and studying their potentially synergistic roles in NF liquor brewing, thus paving the way toward the optimization of liquor production and improvement of liquor quality in future.