复合乳酸菌发酵蛋壳制备乳酸钙

为探索蛋壳碳酸钙发酵制备有机钙,以鸡蛋壳为原料、乳酸钙产量为评价指标,在单因素试验基础上进行Box-Behnken试验设计,优化复合乳酸菌发酵蛋壳制备乳酸钙的工艺条件。结果表明,蒙氏肠球菌、嗜热链球菌、干酪乳杆菌、保加利亚乳杆菌的最佳接种比为 1∶1∶2∶1（体积比）,最佳发酵工艺参数为温度37 ℃、发酵时间72 h、培养基初始pH 6.5、复合菌接种量8.0%。此条件下乳酸钙产量为（40.01±0.035）g/L,纯度为92.65%。傅里叶变换红外光谱、X-射线衍射的结构表征证实发酵产物为乳酸钙。研究结果将为蛋壳钙高效生物转化成乳酸钙提供可行途径与理论参考。     

利用乳酸菌直接发酵生产乳酸钙

用一种耐热高活性乳酸菌（以嗜热链球菌和嗜酸乳杆菌质量配比1：2混合）直接接种到喷射液化、糖化好的玉米浆中,再加碳酸钙直接发酵生成乳酸钙。结果表明,采用此工艺生产乳酸钙反应速度快、转化率高、纯度高、吸收力强,产品属于高活性钙添加剂。     

富硒乳酸菌发酵条件的研究

通过单因素试验和L27(313)正交试验,确定了乳酸菌富硒的最佳发酵条件.正交试验结果表明,影响乳酸菌总硒量的主要因素是培养温度、接种量、亚硒酸钠浓度和培养温度与接种量的一次交互作用.最佳发酵条件为培养基初始pH为6.6,亚硒酸钠浓度为18 μg/mL,装液量为150 mL/250 mL三角瓶,接种量5.5%,培养温度 42 ℃,培养时间45.5 h.在此优化条件下,富硒乳酸菌生物量可达6.85 g/L,细胞硒含量达1100 μg/g,硒总含量可达7536 μg/L,细胞硒含量的92.15%为有机硒.     

产超氧化物歧化酶乳酸菌的筛选及发酵条件优化

从不同地区的传统发酵食品中筛选出104株菌落形态各异的乳酸菌,通过过氧化氢抗性试验筛选出20株具有抗氧化能力的乳酸菌,并测定其产SOD的能力。结果表明,20株乳酸菌中C8的SOD活性最高,达349.62 U/mg。通过革兰氏染色、过氧化氢酶试验和16S rRNA基因序列分析,构建系统发育树,根据同源性分析确定C8为乳酸乳球菌。为提高菌株产SOD的能力,通过单因素实验探究培养温度、初始接种量、初始pH值和灌装量对乳酸乳球菌产SOD的影响,并通过正交试验进一步优化菌株的发酵条件。最终确定最佳发酵条件为:发酵温度37℃,初始接种量3%,初始pH 7.5,灌装量75mL。在此培养条件下,乳酸乳球菌的SOD活性达93.95 U/mL,与优化前相比提高了2.2倍,为后期乳酸乳球菌在发酵产业的应用奠定基础。     

乳酸菌剂发酵泡菜发酵条件研究与优化

在使四川泡菜实现产业化生产过程中,保证乳酸菌剂产品风味的同时,大幅缩短泡菜发酵周期,提高生产效率.研究针对乳酸菌发酵泡菜生产过程中关键工艺之一的发酵工艺进行深入研究,分别以盐投入量、乳酸菌制剂投入量、发酵温度、发酵时间为单因素,以总酸、硬度、感官评分为评价指标,探索不同发酵条件下乳酸菌制剂发酵泡菜品质的变化趋势,得到发酵工艺最佳参数.     

乳酸菌BN1005富硒发酵条件优化

该试验采用单因素试验和响应面试验优化了乳酸菌BN1005富硒发酵条件。结果表明,乳酸菌BN1005富硒的最优培养基组成为葡萄糖39.0 g/L,复合有机氮源15.0 g/L,柠檬酸三铵1.5 g/L,吐温-80 1.08 g/L,K2HPO4 2.0 g/L,MgSO4·7H2O 0.2 g/L,MnSO4·4H2O 0.05 g/L,CaCO3 15.0 g/L,NaCl 3.0 g/L;培养条件为接种量10%,装液量60 mL/250 mL,恒温37 ℃、100 r/min振荡培养36 h,亚硒酸钠5.0 mg/L,亚硒酸钠添加时间8 h。在此优化条件下,乳酸菌BN1005富硒率从7.22%提高至53.81%;富硒量由305.9 μg/g提升至607.52 μg/g。     

乳酸菌发酵牛肉的工艺条件优化

通过单因素试验和响应面方法优化乳酸菌发酵牛肉的工艺,采用乳酸菌(内含保加利亚乳杆菌、嗜热链球菌)对新鲜牛肉进行发酵,对所得牛肉的pH值进行测定.结果表明:乳酸菌发酵牛肉的最佳发酵条件为葡萄糖添加量2.5％、食盐添加量0.3％、乳酸菌添加量2.5％,在酸性环境下进行乳酸菌发酵牛肉,能够有效的抑制微生物生长繁殖,能延长新鲜牛肉的保质期.     

高效水解乳糖乳酸菌的筛选及发酵条件优化

我国新疆地区传统酸马奶中乳酸菌资源丰富,为获得高效降解乳糖的乳酸菌及其发酵条件,本实验从分离自新疆酸马奶的14 株乳酸菌中,筛选出1 株高效水解乳糖的发酵乳杆菌RB-6,其乳糖水解率达37%。进一步利用单因素试验和正交试验对发酵乳杆菌RB-6的发酵温度、接种量和发酵时间进行优化,获得其乳糖水解率最高的发酵条件为：发酵温度39 ℃、接种量3%、发酵时间8 h。发酵乳杆菌RB-6在该条件下发酵酸奶的乳糖水解率达47%,比优化前提高了10%。     

餐厨垃圾中乳酸菌的筛选及其发酵条件的优化

从餐厨垃圾中分离出3种菌,通过形态观察、生理生化鉴定和乳酸定性试验筛选出一株具有溶钙圈的乳酸菌,命名为R,分离纯化并保存。根据发酵液吸光度的测定值绘出该乳酸菌的生长曲线,选择对数期的菌用于餐厨垃圾的乳酸发酵。采用单因素和正交试验对发酵条件进行优化。最后确定最佳发酵条件为:固液比1/9、接种量10%、pH值6.0、温度43℃和发酵时间60h。最终得出加入R1乳酸菌比不加R1乳酸菌的空白对照的乳酸浓度高15.5%。     

南酸枣乳酸菌饮料发酵条件的优化

以南酸枣泥为主要原料,利用复合乳酸菌发酵制成南酸枣饮料,并通过单因素试验和正交试验优化其发酵条件。以总酸、pH值、糖度值、黄酮及VC含量和感官评分为指标探究发酵时间、接种量、发酵温度对南酸枣乳酸菌饮料品质的影响。结果表明,最佳发酵工艺：发酵时间60 h、接种量0.4%、发酵温度37℃。在该条件下南酸枣乳酸菌饮料黄酮含量为3.43 mg/mL,较发酵前提高40%,且口感润滑、酸甜适中并具有浓郁香气。     

低温乳酸菌混菌培养条件的优化

以低温乳酸菌乳酸乳球菌和干酪乳杆菌为研究对象,采用单因素实验、Box-Behnken实验设计对低温乳酸菌混菌培养条件进行优化。结果表明:培养温度、初始pH、接种量对低温乳酸菌活菌数影响均显著（p<0.01）,最优条件为:培养温度24.32℃、初始pH6.60、接种量3.20%,在此条件下活菌数的预测极大值为10.32lgCFU/mL,验证实验的活菌数为（10.25±0.02）lgCFU/mL,与理论预测值相比相对误差约为0.99%。      

Nonstarter lactic acid bacteria and aging temperature affect calcium lactate crystallization in cheddar cheese

The occurrence of unappetizing calcium lactate crystals in Cheddar cheese is a challenge and expense to manufacturers, and this research was designed to understand their origin. It was hypothesized that nonstarter lactic acid bacteria (NSLAB) affect calcium lactate crystallization (CLC) by producing D(-)-lactate. This study was designed to understand the effect of NSLAB growth and aging temperature on CLC. Cheeses were made from milk inoculated with Lactococcus lactis starter culture, with or without Lactobacillus curvatus or L. helveticus WSU19 adjunct cultures. Cheeses were aged at 4 or 13 degrees C for 28 d, then half of the cheeses from 4 and 13 degrees C were transferred to 13 and 4 degrees C, respectively, for the remainder of aging. The form of lactate in cheeses without adjunct culture or with L. helveticus WSU19 was predominantly L(+)-lactate (> 95%, wt/wt), and crystals were not observed within 70 d. While initial lactate in cheeses containingL. curvatus was only L(+)-lactate, the concentration of D(-)-lactate increased during aging. After 28 d, a racemic mixture of D/L-lactate was measured in cheeses containing L. curvatus; at the same time, CLC was observed. The earliest and most extensive CLC occurred on cheeses aged at 13 degrees C for 28 d then transferred to 4 degrees C. These results showed that production of D(-)-lactate by NSLAB, and aging temperature affect CLC in maturing Cheddar cheese.     

啤酒中乳酸细菌分离用培养基的优化

根据乳酸细菌的营养要求,优化了培养基(B-MRS)的成分及用量,确立了B-MRS培养基的配方。通过测定乳酸细菌在B-MRS培养基和MRS培养基中的生长曲线,确定乳酸细菌在B-MRS培养基中的培养终止时间为24h,比MRS培养基提前约10h,且吸光度值OD_(450)达到0．45,酸度达到6．50°T。     

乳酸菌发酵柿汁的制备工艺

介绍了以柿子汁为原料制备乳酸菌发酵饮料的工艺流程,并对原材料和发酵产品的一些营养指标进行了测量。实验表明,乳酸菌发酵的最佳条件是发酵温度30℃、接种量6%、菌种AS1.1482∶6038=2∶1。产品既保留了部分柿子汁的原有风味,又具有乳酸发酵形成的特殊风味,营养价值较高,有一定的保健作用。     

Nonstarter lactic acid bacteria biofilms and calcium lactate crystals in Cheddar cheese

A sanitized cheese plant was swabbed for the presence of nonstarter lactic acid bacteria (NSLAB) biofilms. Swabs were analyzed to determine the sources and microorganisms responsible for contamination. In pilot plant experiments, cheese vats filled with standard cheese milk (lactose:protein = 1.47) and ultrafiltered cheese milk (lactose:protein = 1.23) were inoculated with Lactococcus lactis ssp. cremoris starter culture (8 log cfu/mL) with or without Lactobacillus curvatus or Pediococci acidilactici as adjunct cultures (2 log cfu/mL). Cheddar cheeses were aged at 7.2 or 10°C for 168 d. The raw milk silo, ultrafiltration unit, cheddaring belt, and cheese tower had NSLAB biofilms ranging from 2 to 4 log cfu/100 cm². The population of Lb. curvatus reached 8 log cfu/g, whereas P. acidilactici reached 7 log cfu/g of experimental Cheddar cheese in 14 d. Higher NSLAB counts were observed in the first 14 d of aging in cheese stored at 10°C compared with that stored at 7.2°C. However, microbial counts decreased more quickly in Cheddar cheeses aged at 10°C compared with 7.2°C after 28 d. In cheeses without specific adjunct cultures (Lb. curvatus or P. acidilactici), calcium lactate crystals were not observed within 168 d. However, crystals were observed after only 56 d in cheeses containing Lb. curvatus, which also had increased concentration of d(−)-lactic acid compared with control cheeses. Our research shows that low levels of contamination with certain NSLAB can result in calcium lactate crystals, regardless of lactose:protein ratio.     

响应面法优化复合乳酸菌培养条件

将从青贮饲料中自行分离得到的3株优良乳酸菌组成复合乳酸菌,利用响应面分析法对复合乳酸菌的培养条件进行优化,在单因素试验基础上,根据Box-Behnken Design设计试验,并利用Design Expert 8.0.6软件对模型和各因素的显著性及可信性进行分析,优化后的最佳培养条件为：培养温度37 ℃、初始pH值为7.0、接种量（配比为1∶1∶1）4%。在此最佳条件下,获得的乳酸菌菌落数对数值为9.79。     

酸笋中高产乳酸乳酸菌的筛选、鉴定及发酵条件优化

为获得酸笋中高产乳酸乳酸菌,以柳州传统发酵酸笋为原料,利用MRS培养基对乳酸菌进行分离纯化,然后通过溶钙圈法和高效液相色谱（HPLC）法对高产乳酸乳酸菌进行筛选,并采用形态观察及分子生物学技术对其进行菌种鉴定,最后优化该菌种产乳酸的发酵条件。结果表明,分离并筛选得到一株高产乳酸的乳酸菌菌株LB-1-23,并鉴定其为植物乳杆菌（Lactobacillus plantarum）,该菌株发酵产乳酸的最适条件为接种量2.6%,pH值5.5,发酵温度32 ℃,发酵时间30 h,葡萄糖为碳源,细菌学蛋白胨为氮源。在此优化条件下,乳酸产量为12.74 g/L。该研究为酸笋来源乳酸菌发酵产生乳酸的应用奠定了理论基础。     

侗族酸肉中乳酸菌SR2-2产胞外多糖发酵和提取工艺优化

筛选自贵州侗族酸肉中产胞外多糖的乳酸菌SR2-2,利用单因素结合正交试验对其产胞外多糖的最佳发酵条件及其提取工艺进行研究。结果表明,最佳发酵工艺为蔗糖2%、胰蛋白胨∶蛋白胨=2∶1、发酵温度31 ℃、发酵时间24 h,在此条件下胞外多糖产量为（565.52±6.81） mg/L,较优化前提高了58.32%;胞外多糖最佳提取工艺为：三氯乙酸终含量为10%、加入24 mL无水乙醇沉淀18 h,在此条件下多糖提取量为（790.22±13.00） mg/L,较优化前提高了53.31%。     

蔬菜乳酸菌腌渍发酵过程亚硝酸盐变化研究

研究了蔬菜腌渍发酵过程中添加乳酸菌纯培养液对亚硝酸盐含量变化的影响。实验结果表明,接种乳酸菌能降低蔬菜腌渍发酵过程中亚硝酸盐含量。4组乳酸菌腌渍发酵实验中,接种混合菌种(干酪乳杆菌∶鼠李糖乳杆菌∶植物乳杆菌=1∶1∶1)对蔬菜湿腌发酵时菜料和菜汤的亚硝酸盐含量降低效果最佳,接种植物乳杆菌对蔬菜干腌发酵时菜料亚硝酸盐含量降低作用最显著。