Thermal Protection of Encapsulated Bacillus mucilaginosus
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摘要:
目的 针对胶质芽孢杆菌(Bacillus mucilaginosus)直投式菌剂菌体存活率低及易失活等问题,对喷雾干燥复合抗热保护剂进行优化研究,以期为其菌剂生产提供理论与技术支持。 方法 以直投式菌剂菌体存活率为指标,利用喷雾干燥生产工艺,考察海藻糖、脱脂奶粉、麦饭石改性材料(H-MS)对菌体的抗热保护效果;并利用响应面法对复合抗热保护剂配方进行优化。 结果 不添加抗热保护剂的菌剂菌体存活率仅有(34.15±1.07)%;添加单一保护剂时,以海藻糖保护效果最佳,麦饭石改性材料(H-MS)及脱脂奶粉次之,菌体存活率分别可达(52.17±1.08)%,(51.64±0.77)%,(43.67±1.62)%,海藻糖和H-MS对菌体存活率具有极显著影响(P<0.01),脱脂奶粉对菌体存活率具有显著影响(P<0.05)。利用响应面优化得到最佳复合抗热保护剂配方为海藻糖4.33%、脱脂奶粉2.90%和麦饭石改性材料(H-MS)7.57%。在此最佳添加配比下,菌体存活率为(73.32±0.76)%,活菌数最高可达1.12×109 CFU·g−1。 结论 添加3种抗热保护剂均能提高直投式菌剂菌体存活率,且三者之间存在交互作用,复合使用的抗热效果优于单独使用。扫描电镜观察显示海藻糖和脱脂奶粉将菌体包埋成微胶囊固定在麦饭石改性材料(H-MS)的孔道中,能有效保护菌体细胞,提高菌剂菌体存活率。 Abstract:Objective Effect of encapsulation to protect Bacillus mucilaginosus from thermal shock was evaluated for formulation optimization. Method Rates of survival and activation of B. mucilaginosus encapsulated with trehalose, skimmed milk powder, and/or modified H-MS medical stone after spray-drying were determined. Optimal formulation for the encapsulation was obtained using the response surface method. Result The survival rate of the naked B. mucilaginosus was (34.15±1.07)%. In contrast, the encapsulation with trehalose significantly improved the rate to (52.17±1.08)% (P<0.01), while with H-MS, (51.64±0.77)% (P<0.01) and with skimmed milk powder, (43.67±1.62)% (P<0.05). Furthermore, a combined use of trehalose at 4.33%, skimmed milk powder at 2.90%, and H-MS at 7.57% for the encapsulation, the survival reached (73.32±0.76)% with a microbial count of 1.12×109 CFU·g−1. Conclusion The three encapsulation materials, especially, when they were applied in combination, significantly raised the B. mucilaginosus survival rate under a heat treatment. The scanning electron microscopic image revealed that trehalose and skimmed milk powder immobilized the bacteria cells in H-MS pores producing an effective thermal insulation that sheltered the encapsulated microbes. -
图 2 不同抗热保护剂处理下菌剂含水率
不同小写字母表示差异显著(P<0.05);CK:空白;A:海藻糖;B:脱脂奶粉;C:H-MS;D:复合保护剂。
Figure 2. Moisture content of B. mucilaginosus encapsulated with various protectants
Data with different lowercase letters indicate significant differences (P<0.05); CK: blank control; A: trehalose; B: skimmed milk powder; C: H-MS; D: combination protectant.
表 1 Box-Behnken试验设计因素水平
Table 1. Factor levels in Box-Behnken experiment design
水平
Level因素 Factor A 海藻糖
Trehalose/%B 脱脂奶粉 Skimmed
milk powder/%C H-MS/% −1 2 2 6 0 4 3 8 1 6 4 10 表 2 单因素试验结果
Table 2. Results of single factor experiment
抗热保护剂
Anti-thermal
protectant添加质量分数
Appending
proportion/%菌体存活率
Bacterial survival
rate/%空白
Blank0 34.15±1.07 海藻糖
Trehalose2 41.65±2.66 c 4 52.17±1.08 a 6 50.84±1.22 ab 8 48.17±1.95 b 脱脂奶粉
Skimmed milk powder1 36.25±2.27 b 2 39.78±1.73 ab 3 43.67±1.62 a 4 41.39±2.25 a H-MS 6 47.18±1.72 c 8 51.64±0.77 a 10 50.68±0.86 ab 12 48.96±1.30 bc 同一处理组内不同小写字母表示差异显著(P<0.05)。
Different lowercase letters within the same numbered group indicate significant differences (P<0.05).表 3 Box-Behnken试验设计及结果
Table 3. Box-Behnken experimental design and results
试验号
Test numberA因素
A-factor levelB因素水平
B-factor levelC因素
C-factor level菌体存活率
Bacterial survival rate/%1 −1 −1 0 54.86 2 −1 1 0 60.14 3 1 −1 0 64.43 4 1 1 0 55.38 5 −1 0 −1 56.23 6 1 0 −1 67.53 7 −1 0 1 59.16 8 1 0 1 56.24 9 0 −1 −1 62.47 10 0 1 −1 64.61 11 0 −1 1 64.47 12 0 1 1 58.12 13 0 0 0 73.54 14 0 0 0 72.84 15 0 0 0 71.84 表 4 回归模型方差分析
Table 4. Analysis of variance of regression model
方差来源
Variance source自由度
Freedom离差平方和
Sum of squares均方
Mean squareF值
F valueP值
P value修正模型 Model 9 570.65 63.41 64.05 0.0001 A 1 21.75 21.75 21.97 0.0054 B 1 7.96 7.96 8.04 0.0364 C 1 20.64 20.64 20.85 0.0060 AB 1 51.34 51.34 51.86 0.0008 AC 1 50.55 50.55 51.07 0.0008 BC 1 18.02 18.02 18.20 0.0080 A2 1 256.36 256.36 258.98 < 0.0001 B2 1 120.17 120.17 121.40 0.0001 C2 1 78.72 78.72 79.53 0.0003 残差 Residual 5 4.95 0.99 失拟项 Lack of fit 3 3.49 1.16 1.59 0.4080 纯误差 Pure error 2 1.46 0.73 总计 Total 14 575.60 -
[1] 田稼, 吴小杰, 孙超, 等. 胶质芽孢杆菌(Bacillus mucilaginosus)的研究进展 [J]. 中国土壤与肥料, 2017(6):15−22. doi: 10.11838/sfsc.20170603TIAN J, WU X J, SUN C, et al. Research progress on Bacillus mucilaginosus [J]. Soil and Fertilizer Sciences in China, 2017(6): 15−22.(in Chinese) doi: 10.11838/sfsc.20170603 [2] MUSAH B I, PENG L, XU Y F. Biosorption of Cr (VI) using Bacillus licheniformis and Bacillus mucilaginosus Krassilnikov: Contrastive investigation on removal performance, kinetics, and mechanisms [J]. Environmental Engineering Science, 2021, 38(4): 231−244. doi: 10.1089/ees.2020.0190 [3] 杨榕, 李博文, 刘微. 胶质芽孢杆菌对印度芥菜富集土壤Cd及土壤pH的影响 [J]. 环境科学学报, 2013, 33(6):1648−1654.YANG R, LI B W, LIU W. Effects of Bacillus mucilaginosus on soil pH and Cd accumulation by Brassica juncea [J]. Acta Scientiae Circumstantiae, 2013, 33(6): 1648−1654.(in Chinese) [4] BASAK B B, MAITY A, RAY P, et al. Potassium supply in agriculture through biological potassium fertilizer: A promising and sustainable option for developing countries [J]. Archives of Agronomy and Soil Science, 2022, 68(1): 101−114. doi: 10.1080/03650340.2020.1821191 [5] 李宝磊. 真空冷冻干燥对乳酸菌损伤机制及关键保护技术研究[D]. 哈尔滨: 哈尔滨工业大学, 2011.LI B L. Freeze-drying damage mechanism of lactic acid bacteria and the key protection technology research[D]. Harbin: Harbin Institute of Technology, 2011. (in Chinese) [6] 贺金梅, 刘俊轩, 孙颖, 等. 固态微生物菌剂干燥和菌体保存的研究进展 [J]. 食品工业科技, 2012, 33(15):423−427.HE J M, LIU J X, SUN Y, et al. Research progress in drying of solid microbial agent and protection of cell [J]. Science and Technology of Food Industry, 2012, 33(15): 423−427.(in Chinese) [7] 关鹏翔. 哈密瓜果粉喷雾干燥工艺及品质研究[D]. 杭州: 浙江工商大学, 2013.GUAN P X. Studies on the spray drying technology of cantaloup juice powder and relative quality research[D]. Hangzhou: Zhejiang Gongshang University, 2013. (in Chinese) [8] WANG N, FU N, CHEN X D. The extent and mechanism of the effect of protectant material in the production of active lactic acid bacteria powder using spray drying: A review [J]. Current Opinion in Food Science, 2022, 44: 100807. doi: 10.1016/j.cofs.2022.01.003 [9] KAWAKITA R, LEVEAU J H J, JEOH T. Optimizing viability and yield and improving stability of Gram-negative, non-spore forming plant-beneficial bacteria encapsulated by spray-drying [J]. Bioprocess and Biosystems Engineering, 2021, 44(11): 2289−2301. doi: 10.1007/s00449-021-02604-9 [10] 赵彦巧, 王月, 孟翔宇, 等. 喷雾干燥法制备玫瑰茄花色苷微胶囊条件优化 [J]. 福建农业学报, 2021, 36(1):104−114.ZHAO Y Q, WANG Y, MENG X Y, et al. Optimized preparation of spray-dried anthocyanins microcapsules [J]. Fujian Journal of Agricultural Sciences, 2021, 36(1): 104−114.(in Chinese) [11] KHEM S, SMALL D M, MAY B K. The behaviour of whey protein isolate in protecting Lactobacillus plantarum [J]. Food Chemistry, 2016, 190: 717−723. doi: 10.1016/j.foodchem.2015.06.020 [12] 张武, 董春霞, 纪妍妍. 石油降解菌的固定化材料研究进展 [J]. 材料导报, 2017, 31(S2):214−218.ZHANG W, DONG C X, JI Y Y. Progress of research on carrier materials for oil degrading bacteria immobilization [J]. Materials Review, 2017, 31(S2): 214−218.(in Chinese) [13] SOUKOULIS C, BEHBOUDI-JOBBEHDAR S, YONEKURA L, et al. Impact of milk protein type on the viability and storage stability of microencapsulated Lactobacillus acidophilus NCIMB 701748 using spray drying [J]. Food and Bioprocess Technology, 2014, 7(5): 1255−1268. doi: 10.1007/s11947-013-1120-x [14] ALVARENGA V O, CAMPAGNOLLO F B, PIA A K R, et al. Quantifying the responses of three Bacillus cereus strains in isothermal conditions and during spray drying of different carrier agents [J]. Frontiers in Microbiology, 2018, 9: 1113. doi: 10.3389/fmicb.2018.01113 [15] SOMPACH G, RODKLONGTAN A, NITISINPRASERT S, et al. Microencapsulating role of whey protein isolate and sucrose in protecting the cell membrane and enhancing survival of probiotic lactobacilli strains during spray drying, storage, and simulated gastrointestinal passage [J]. Food Research International, 2022, 159: 111651. doi: 10.1016/j.foodres.2022.111651 [16] AGUDELO J, CANO A, GONZÁLEZ-MARTÍNEZ C, et al. Disaccharide incorporation to improve survival during storage of spray dried Lactobacillus rhamnosus in whey protein-maltodextrin carriers [J]. Journal of Functional Foods, 2017, 37: 416−423. doi: 10.1016/j.jff.2017.08.014 [17] 张雯, 王芳婷, 庞锦程, 等. 枯草芽孢杆菌BS08复合抗热保护剂的工艺配方优化 [J]. 食品与发酵工业, 2022, 48(17):35−41. doi: 10.13995/j.cnki.11-1802/ts.029713ZHANG W, WANG F T, PANG J C, et al. Formulation optimization of compound anti-thermal protectant of Bacillus subtilis BS08 [J]. Food and Fermentation Industries, 2022, 48(17): 35−41.(in Chinese) doi: 10.13995/j.cnki.11-1802/ts.029713 [18] 孙丛, 付瑶, 王娅丽, 等. 喷雾干燥法制备阿特拉津降解菌剂条件优化 [J]. 中国农学通报, 2018, 34(35):86−92. doi: 10.11924/j.issn.1000-6850.casb18060002SUN C, FU Y, WANG Y L, et al. Optimization of atrazine degradation bacteria by spray drying [J]. Chinese Agricultural Science Bulletin, 2018, 34(35): 86−92.(in Chinese) doi: 10.11924/j.issn.1000-6850.casb18060002 [19] 赵月, 杨亚楠, 李雅华, 等. 生防细菌蜡样芽孢杆菌BCCY-22发酵条件优化 [J]. 福建农业学报, 2022, 37(7):938−945.ZHAO Y, YANG Y N, LI Y H, et al. Optimizing fermentation of biocontrol bacterium Bacillus cereus BCCY-22 [J]. Fujian Journal of Agricultural Sciences, 2022, 37(7): 938−945.(in Chinese) [20] SIDDIQUI Z S, ALI F, UDDIN Z. Sustainable effect of a symbiotic nitrogen-fixing bacterium Sinorhizobium meliloti on nodulation and photosynthetic traits of four leguminous plants under low moisture stress environment [J]. Letters in Applied Microbiology, 2021, 72(6): 714−724. doi: 10.1111/lam.13463 [21] 林金新, 蔡少丽, 王芳婷, 等. 白酒丢糟的多菌种混菌固态发酵制备有机肥 [J]. 福建师范大学学报(自然科学版), 2017, 33(3):69−77.LIN J X, CAI S L, WANG F T, et al. Optimization on process condition in solid-state fermentation of vinasse for organic fertilizer [J]. Journal of Fujian Normal University (Natural Science Edition), 2017, 33(3): 69−77.(in Chinese) [22] GORSUCH J P, JONES Z, SAINT D L, et al. Enumeration of industrial Bacillus assemblages in commercial products with customized plate-counting assays [J]. Journal of Microbiological Methods, 2019, 164: 105682. doi: 10.1016/j.mimet.2019.105682 [23] 陆璐. 微生态制剂工大2号包埋与喷雾干燥工艺研究[D]. 大连: 大连工业大学, 2018LU L. Study on embedding and spray drying process of probiotic gongda Ⅱ[D]. Dalian: Dalian Polytechnic University, 2018. (in Chinese) [24] 肖怀秋, 李玉珍, 林亲录, 等. 枯草芽孢杆菌Prob1822复合抗热保护剂的研究 [J]. 中国酿造, 2019, 38(10):49−54. doi: 10.11882/j.issn.0254-5071.2019.10.011XIAO H Q, LI Y Z, LIN Q L, et al. Compound anti-thermal protectant of Bacillus subtilis Prob1822 [J]. China Brewing, 2019, 38(10): 49−54.(in Chinese) doi: 10.11882/j.issn.0254-5071.2019.10.011 [25] KHATIB I, CHOW M Y T, RUAN J F, et al. Modeling of a spray drying method to produce ciprofloxacin nanocrystals inside the liposomes utilizing a response surface methodology: Box-Behnken experimental design [J]. International Journal of Pharmaceutics, 2021, 597: 120277. doi: 10.1016/j.ijpharm.2021.120277 [26] 傅楠, 陈晓东. 益生菌在喷雾干燥过程中的活性变化与保护策略 [J]. 化工进展, 2018, 37(5):1633−1645.FU N, CHEN X D. Changes in the viability of probiotics during spray drying process and the strategies to protect probiotic cells [J]. Chemical Industry and Engineering Progress, 2018, 37(5): 1633−1645.(in Chinese) [27] ARSLAN S, ERBAS M, TONTUL I, et al. Microencapsulation of probiotic Saccharomyces cerevisiae var. boulardii with different wall materials by spray drying [J]. LWT - Food Science and Technology, 2015, 63(1): 685−690. doi: 10.1016/j.lwt.2015.03.034 [28] 周庆, 陈杏娟, 许玫英. 微生物菌剂在难降解有机污染治理的研究进展 [J]. 微生物学通报, 2013, 40(4):669−676.ZHOU Q, CHEN X J, XU M Y. Recent research progress in microbial agents for treatment of refractory organic contaminants [J]. Microbiology China, 2013, 40(4): 669−676.(in Chinese)