7株野生虫草菌的鉴定及其菌丝体醇提取物对HepG2细胞的抑制活性

结合形态学与ITS序列分析对7株野生虫草真菌进行分类鉴定。MTT法分析它们的菌丝体醇提取物对肝癌HepG2细胞增殖的抑制活性。鉴定结果表明菌株MF7、MF9、MF14为细脚棒束孢Isaria tenuipes,菌株MF11、MF12、MF13为蝉棒束孢Isaria cicadae,菌株MF10为球孢白僵菌Beauveria bassiana;MTT结果显示分离到的3株细脚棒束孢和3株蝉棒束孢的菌丝体醇提取物对HepG2的抑制活性较差,IC₅₀均大于500μg/mL;球孢白僵菌MF10对HepG2细胞有一定抑制作用,IC₅₀值为221.6μg/mL,略强于蝙蝠蛾拟青霉发酵菌丝粉产品金水宝胶囊（IC₅₀=364μg/mL）和中华被毛孢发酵菌丝粉产品百令胶囊（IC₅₀=268.7μg/mL）。另外,发现供对比试验的3株蛹虫草菌株（MF1、MF5、MF15）对HepG2细胞均有较好的抑制作用,其中MF15的发酵菌丝体醇提取物活性最强,IC₅₀为55.56μg/mL,暗示蛹虫草发酵菌丝体具有重要的研究价值。     

农杆菌介导Txpam基因转化烟曲霉TMS-26及其产紫杉醇效果评价

为研究红豆杉紫杉醇合成途径限速酶基因功能及其对内生真菌烟曲霉TMS-26发酵产紫杉醇的影响,以曼地亚红豆杉愈伤组织制备cDNA作为模板扩增苯丙氨酸氨基变位酶基因（Txpam）,构建重组质粒pGEX-4T-1-Txpam,转入大肠杆菌中进行异源诱导表达,经亲和层析纯化,获取重组酶TxPAM并验证其酶活性。构建pCAMBIA1302-Txpam质粒,转化农杆菌感受态细胞,利用农杆菌介导的转化体系获得转化子并优化转化条件,结合插入片段携带的分子标记和目的基因进行转化子验证,同时培养转化菌株并检测紫杉醇产量。结果表明：纯化获取的重组酶TxPAM,经HPLC检测具有将α-苯丙氨酸催化为β-苯丙氨酸的功能;在最优转化条件下,转化子数目达到471个/10⁶个孢子;根据基因hyg和Txpam的克隆以及测序结果,说明成功构建了基因工程菌株,通过对其发酵条件进行优化,紫杉醇产量达到721.87μg/L。     

三种分离自冬虫夏草真菌及培养条件

对采自青海玉树、青海果洛和云南迪庆的冬虫夏草鲜品进行虫生真菌的分离、纯化,获得3种生长形态不同的真菌QH 2019、GL 2019和YN 2019。通过形态学及分子鉴定,菌株QH 2019为蝙蝠蛾拟青霉Samsoniella hepiali,菌株GL 2019为粉棒束孢Isaria farinosa,菌株YN 2019为玫烟色棒束孢Isaria fumosorosea。对这3株菌的培养条件初步研究,结果表明：菌株QH 2019在1/4 SDAY培养基上菌丝日生长速率最快,为(1.94±0.55)mm/d,且菌丝致密、粗壮,含水率高达(91.90±1.22)%,虫草素和虫草酸均以PDA培养的含量最高,分别为(0.47±0.022)mg/g和(3.24±0.021)mg/g;菌株GL 2019在PDA培养基上菌丝日生长速率、菌丝含水率、虫草素含量和虫草酸含量都最高,分别为(2.37±0.20)mm/d、(88.34±2.00)%、(0.23±0.013)mg/g和(6.92±0.019)mg/g,但其菌丝在1/4 SDAY培养基上生长最为致密、粗壮;菌株YN 2019在PDA培养基上菌丝日生长速率、虫草素和虫草酸的含量最高,分别为：(2.27±0.27)mm/d、(0.50±0.012)mg/g和(11.32±0.16)mg/g,但其菌丝在1/4 SDAY培养基上含水率最高(95.23±1.65)%,且生长最为致密、粗壮。综合评价表明3株真菌中YN 2019菌丝中虫草素和虫草酸的含量高、生长速率快,有较好的药用研究价值。     

烟曲霉TMS-26产紫杉醇补料分批发酵条件初步探索

内生真菌发酵法是解决紫杉醇药源短缺问题的有效途径之一。本研究以摇瓶分批发酵为基础,进行摇瓶补料分批发酵研究,探究了苯丙氨酸、甘氨酸、苯甲酸钠乙酸钠混合液、3,5-二硝基水杨酸、H₂O₂、CuSO₄在发酵周期（13d）中,不同添加时间点对TMS-26菌体量及紫杉醇产量的影响,发现在第8天添加苯丙氨酸、甘氨酸、3,5-二硝基水杨酸时,其产量分别达到了(664.80±40.34)µg/L、(628.72±30.44)µg/L、(641.36±19.62)µg/L;在第9天添加CuSO₄时,其产量达到了(697.46±15.76)µg/L;在第10天添加H₂O₂、苯甲酸钠乙酸钠混合液,其产量分别达到了(615.78±36.28)µg/L、(792.54±10.04)µg/L。在摇瓶补料分批发酵研究结果的基础上,进行了5L罐发酵工艺放大研究,探究了前体和诱导子通过进行一次补加和恒速补加的方式对Aspergillus fumigatus TMS-26菌体量及紫杉醇产量的影响,结果表明恒速补加苯丙氨酸乙酸钠混合液,紫杉醇产量达到了746.17µg/L。通过本次研究,优化了TMS-26产紫杉醇摇瓶补料分批发酵和5L罐发酵工艺,为后续实现紫杉醇工业化生产奠定基础。     

解脂耶氏酵母诱变育种及发酵产α-酮戊二酸条件优化

对具有发酵产α-酮戊二酸能力的解脂耶氏酵母(Yarrowia Lipolytica)ZY-4进行了紫外诱变和NTG诱变育种,筛选得到产量提高的突变株,并对突变株的发酵培养基进行了优化,结果表明,紫外诱变和NTG诱变后筛选到的突变株分别比原始出发菌株产量提高了67.8%和110%。优化后发酵培养基成分为甘油8%,氯化铵5.0 g/L,硫胺素1.0μg/L,磷酸二氢钾1.0 g/L,七水硫酸镁0.5 g/L,培养基优化后α-酮戊二酸产量比原始出发菌株提高了232.4%。     

优良性状蚕蛹虫草的筛选及高产虫草素液态发酵条件优化

蛹虫草是重要的食药用真菌,虫草素为其主要活性成分,在抗肿瘤、抗菌、降血糖等方面具有较为突出的功效。蛹虫草菌株间的形态及环境条件差异,对菌株次级代谢产物虫草素产生影响显著。本研究对不同来源的6株蛹虫草菌株（YCC-B、YCC-C、YCC-H、YCC-W、YCC-Y、CGMCC 3.4655）,从蚕蛹体培养子实体性状,液体发酵条件（培养天数、培养方式、外源金属离子等）和传代稳定性等方面筛选优良性状菌株,提高其发酵合成虫草素的能力及稳定性。结果表明,蛹虫草菌株YCC-W在蚕蛹子实体出草及菌体液体发酵产虫草素上综合表现优良,传代稳定;液体发酵培养基中添加外源金属离子Mn²⁺作为酶的辅基,可以促进虫草素合成;采用振荡-静置相结合的混合发酵培养方式,可以避免单纯振荡培养溶氧量大、菌丝体生长旺盛,而虫草素产生不佳的问题。先振荡培养3d后静置培养至25d时,菌株YCC-W合成虫草素含量最高,可达(874.13±24.25)μg/mL,且稳定性良好。为进一步开发菌种及扩大规模生产提供参考。     

古尼虫草胞内多糖高产培养基优化研究

以古尼虫草Cordyceps gunnii胞内多糖产量为目标,利用单因素法筛选古尼虫草产胞内多糖的最适碳源、氮源和无机盐,运用正交试验筛选最佳培养基组合,用最佳培养基研究古尼虫草产胞内多糖的发酵动力学。结果表明：古尼虫草产胞内多糖最佳培养基为葡萄糖35g/L、蛋白胨15g/L、硫酸锌1g/L、KH₂PO₄ 1g/L、K₂HPO₄ 0.5g/L,用最佳培养基获得胞内多糖（5.169±0.274）g/L,产量是优化前的1.81倍;动力学研究表明,144h是古尼虫草胞内多糖最佳培养时间,此时产量最高为（6.794±0.221）g/L,是目前报道古尼虫草胞内多糖的最高产量。     

前体及诱导子和发酵条件对烟曲霉TMS-26产紫杉醇发酵体系优化

紫杉醇是一种广谱的抗癌药物,因其具有独特的抗癌机制、良好的抗癌效果和供不应求的市场等特征而备受关注。紫杉醇具有重大经济效益,但产量受到制约,价格极为昂贵,通过内生真菌发酵法生产紫杉醇能在一定程度上缓解其来源困难的问题。在产紫杉醇内生真菌TMS-26发酵液中添加前体物质和诱导子,并通过对接种量、装液量、初始pH和发酵时间等条件进行优化研究。单因素及正交试验表明在PDB培养基中加入苯丙氨酸20mg/L、苯甲酸钠30mg/L、乙酸钠8g/L、甘氨酸15mg/L、CuSO₄ 0.05mg/L、H₂O₂ 6mmol/L、3,5-二硝基水杨酸15mg/L时能有效提高紫杉醇产量,比优化前增产46.64%,达到446.28µg/L,并且发现最适菌株TMS-26的发酵条件为pH7.5、接种量5%、装液量120mL/250mL、发酵时间为10d。     

牛樟芝多糖对HepG2细胞酒精性氧化损伤的保护作用

研究了不同剂量（100、200和400μg/mL）的牛樟芝粗多糖（CP）和醇提物后的水提物（WEE）对酒精诱导的HepG2细胞氧化损伤的保护作用。研究结果表明：与模型组比较,各剂量组的CP和200、400μg/mL的WEE均能极显著提高HepG2细胞的细胞活力。100μg/mL的CP和WEE均能极显著降低细胞培养液的ALT水平;200和400μg/mL的CP和WEE均能显著降低细胞培养液的ALT、AST水平,同时提高胞内的CAT活力;200和400μg/mL的WEE及400μg/mL CP能明显提高胞内的SOD活力。此外,WEE各剂量组和400μg/mL CP中的胞内ROS水平显著下降。CP中含有甘露糖、鼠李糖、葡萄糖、半乳糖、岩藻糖5种单糖,摩尔比为1:0.1622:6.651:2.646:0.3929。WEE和CP能提高细胞的抗氧化应激能力,降低胞内ROS,对酒精诱导的HepG2细胞氧化损伤起到明显的保护作用,提示多糖是牛樟芝解酒保肝的重要活性成分之一。     

β-葡聚糖酶高产菌株BS9418F的选育及其发酵条件的研究

经60 Coγ射线辐照处理获得的诱变菌株芽孢杆菌BS9418F ,其产酶活力比出发菌株提高 30 %以上。该菌株以大麦粉 7%、玉米粉 3%、豆粕 3%及适量无机盐为培养基最佳配比 ,其最适培养条件为 :培养基初始 pH 7.0 ,摇瓶装量 5 0mL/ 30 0mL三角瓶 ,种龄 16～ 2 0h ,接种量 2 %～ 3% ,培养温度 36～ 37℃ ,发酵周期 40h。在优化条件下 ,摇瓶发酵产 β 葡聚糖酶活力高达 5 5 0 0u/mL以上 ,比出发菌株初始发酵水平提高了 4倍以上     

北亚热带地带性森林土壤温室气体通量对土地利用方式改变和降水减少的响应

弄清土地利用和降水变化对林地土壤主要温室气体(CO₂、CH₄和N₂O)排放通量变化的影响, 是准确评估森林土壤温室气体排放能力的重要基础。该研究以常绿落叶阔叶混交林原始林、桦木(Betula luminifera)次生林和马尾松(Pinus massoniana)人工林为对象, 采用静态箱-气相色谱法研究了3种土地利用方式(常绿落叶阔叶混交林原始林、桦木次生林和马尾松人工林)和降水减少处理状况下森林土壤CO₂、CH₄和N₂O通量排放特征, 并探讨了其环境驱动机制。研究结果表明: 原始林土壤CH₄吸收通量显著高于次生林和人工林, 次生林CH₄吸收通量显著高于人工林土壤。人工林土壤CO₂排放通量显著高于原始林和次生林土壤。次生林土壤N₂O排放通量高于原始林和人工林, 但三者间差异不显著。降水减半显著抑制了3种不同土地利用方式下林地土壤CH₄吸收通量; 降水减半处理对原始林和次生林土壤CO₂排放通量均具有显著的促进作用, 而对人工林土壤CO₂排放通量具有显著的抑制作用; 降水减半处理促进了原始林和人工林林地土壤N₂O排放而抑制了次生林林地土壤N₂O排放。原始林和次生林林地土壤CH₄吸收通量随土壤温度升高显著增加, CH₄吸收通量与土壤温度均呈显著相关关系; 原始林、次生林和人工林土壤CO₂和N₂O排放通量与土壤温度均呈显著正相关关系; 土壤湿度抑制了次生林和人工林土壤CH₄吸收通量, 其CH₄吸收通量随土壤湿度增加显著减少; 原始林土壤CO₂排放通量与土壤湿度呈显著正相关关系。自然状态下, 原始林土壤N₂O排放通量与土壤湿度呈显著正相关关系, 原始林和次生林土壤N₂O排放通量与硝态氮含量呈显著相关关系。研究结果表明全球气候变化(如降水变化)和土地利用方式的转变将对北亚热带森林林地土壤温室气体排放通量产生显著的影响。     

Greenhouse gas fluxes of typical northern subtropical forest soils: Impacts of land use change and reduced precipitation

Aims It is important to study the effects of land use change and reduced precipitation on greenhouse gas fluxes (CO₂, CH₄ and N₂O) of forest soils. Methods The fluxes of CO₂, CH₄ and N₂O and their responses to environmental factors of primary forest soil, secondary forest soil and artificial forest soil under a reduced precipitation regime were explored using the static chamber and gas chromatography methods during the period from January to December in 2014. Important findings Results indicate that CH₄ uptake of primary forest soil ((-44.43 ± 8.73) μg C·m^-2·h^-1) was significantly higher than that of the secondary forest soil ((-21.64 ± 4.86) μg C·m^-2·h^-1) and the artificial forest soil ((-10.52 ± 2.11) μg C·m^-2·h^-1). CH₄ uptake of the secondary forest soil ((-21.64 ± 4.86) μg C·m^-2·h^-1) was significantly higher than that of the artificial forest ((-10.52 ± 2.11) μg C·m^-2·h^-1). CO₂ emissions of the artificial forest soil ((106.53 ± 19.33) μg C·m^-2·h^-1) were significantly higher than that of the primary forest soil ((49.50 ± 8.16) μg C·m^-2·h^-1) and the secondary forest soil ((63.50 ± 5.35) μg C·m^-2·h^-1) (p < 0.01). N₂O emissions of the secondary forest soil ((1.91 ± 1.22) μg N·m^-2·h^-1) were higher than that of the primary forest soil ((1.40 ± 0.28) μg N·m^-2·h^-1) and the artificial forest soil ((1.01 ± 0.86) μg N·m^-2·h^-1). Reduced precipitation (-50%) had a significant inhibitory effect on CH₄ uptake of the artificial forest soil, while it enhanced CO₂ emissions of the primary forest soil and the secondary forest soil. Reduced precipitation had a significant inhibitory effect on CO₂ emissions of the artificial forest soil and N₂O emissions of the secondary forest (p < 0.01). Reduced precipitation promotes N₂O emissions of the primary forest soil and the artificial forest soil. CH₄ uptake of the primary forest and the secondary forest soil increased significantly with the increase of soil temperature under natural and reduced precipitation. CO₂ and N₂O emission fluxes of the primary forest soil, secondary forest soil and artificial forest soil were positively correlated with soil temperature (p < 0.05). Soil moisture inhibited CH₄ uptake of the secondary forest soil and the artificial forest soil (p < 0.05). CO₂ emissions of the primary forest soil were significantly positively correlated with soil moisture (p < 0.05). N₂O emissions of primary forest soil and secondary forest soil were significantly correlated with the nitrate nitrogen content (p < 0.05). It was implied that reduced precipitation and land use change would have significant effects on greenhouse gas emissions of subtropical forest soils.     

Relationship between cellular RecA protein concentration and untargeted mutagenesis in Escherichia coli

We measured the production of untargeted mutations in the cI and cII genes of untreated λ phage undergoing a lytic cycle in UV-irradiated bacterial hosts. As previously shown, treatment with 4 μg/ml of rifampicin during post-irradiation incubation inhibited amplification of the RecA protein in these cells. In addition, we observed a decreased mutation rate compared to the untreated, irradiated bacteria. Treatment with 4 μg/ml or 8 μg/ml rifampicin did not prevent the UV induction of the umuDC operon, as judged by assay of β-galactosidase activity in a umuC-lacZ fusion strain. In contrast, the UV-induction of β-galactosidase in the sulA-lacZ fusion strain was decreased by 4 μg/ml rifampicin. The inhibition of untargeted mutagenesis by this drug treatment was also observed in a strain constitutive for SOS functions (lexA (Def)) as well as ina RecA-overproducing plasmid strain, that blocks induction of heat-shock proteins, factor(s) in wild-type recA⁺ cells. An htpR165-carrying strain, that blocks induction of heat-shock proteins, exhibited normal UV-promoted mutagenesis. A correlation was observed between the cellular concentration of RecA protein, increased spontaneously by a temperature shift in a lexA(Ts) strain, and the extent of UV-promoted untargeted mutagenesis. These results suggest a mechanistic role of RecA protein in this process.     

Effervescence Assisted Fusion Technique to Enhance the Solubility of Drugs

The solubility of five poorly soluble drugs was enhanced by using an effervescence assisted solid dispersion (EASD) technique. EASDs were prepared by using modified fusion method. Drug and hydrophilic carrier were melted, and in this molten mixture, effervescence was generated by adding effervescence couple comprising organic acid (citric acid) and carbonic base (sodium bicarbonate). Solubility of drug powders, solid dispersions, and EASDs was determined at 25°C using shake flask method. Atorvastatin calcium, cefuroxime axetil, clotrimazole, ketoconazole, and metronidazole benzoate were estimated using a spectrophotometer at 246, 280, 260, 230, and 232 nm (λ_max), respectively. Solubility of atorvastatin calcium (from 100 to 345 μg/ml), cefuroxime axetil (from 441 to 1948 μg/ml), clotrimazole (from 63 to 677 μg/ml), ketoconazole (from 16 to 500 μg/ml), and metronidazole benzoate (from 112 to 208 μg/ml) in EASDs was enhanced by 3.45-, 4.4-, 10.7-, 31.2-, and 1.8-fold, respectively. Scanning electron micrographs of drug powder, solid dispersion, and EASDs were compared. Scanning electron micrographs of EASDs showed a uniform distribution of drug particles in the carrier matrix. Morphology (size and shape) of cefuroxime axetil particles was altered in solid dispersion as well as in EASD. EASDs showed better solubility enhancement than conventional solid dispersions. The present technique is better suitable for drugs having a low melting point or melt without charring. Effervescence assisted fusion technique of preparing solid dispersions can be employed for enhancing solubility, dissolution, and bioavailability of poorly soluble drugs.KEY WORDS: dissolution, effervescence, fusion, solid dispersion, solubility     

Polynuclear copper(II) complexes with μ2-1,1-azide bridges. Structural and magnetic properties

Two novel, weakly antiferromagnetically coupled, tetranuclear copper(II) complexes [Cu₄(PAP)₂(μ₂-1,1-N₃)₂(μ₂-1,3-N₃)₂(μ₂-CH₃OH)₂(N₃)₄ (1) (PAP = 1,4-bis-(2′-pyridylamino)phthalazine) and [Cu₄(PAP3Me)₂ (μ₂-1,1-N₃)₂(μ₂-1,3-N₃)₂(H₂O)₂(NO₂)₂]- (NO₃)₂ (2) (PAP3Me = 1,4-bis-(3′-methyl-2′-pyridyl)aminophthalazine) contain a unique structural with two μ₂-1,1-azide intramolecular bridges, and two μ₂-1,3-azide intermolecular bridges linking pairs of copper(II) centers. Four terminal azide groups complete the five-coordinate structures in 1, while two terminal waters and two nitrates complete the coordination spheres in 2. The dinuclear complexes [Cu₂(PPD)(μ₂-1,1-N₃)(N₃)₂(CF₃SO₃)]CH₃OH) (3) and [Cu₂(PPD)(μ₂-1,1-N₃)(N₃)₂(H₂O)(ClO₄)] (4) (PPD = 3,6-bis-(1′-pyrazolyl)pyridazine) contain pairs of copper centers with intramolecular μ₂-1,1-azid and pyridazine bridges, and exhibit strong antiferromagnetic coupling. A one-dimensional chain structure in 3 occurs through intermolecular μ₂-1,1-azide bridging interactions. Intramolecular Cu-N₃-Cu bridge angles in 1 and 2 are small (107.9 and 109.4°, respectively), but very large in 3 and 4 (122.5 and 123.2°, respectively), in keeping with the magnetic properties. 2 crystallizes in the monoclinic system, space group C2/c with a = 26.71(1), b = 13.51(3), c = 16.84(1) Å, β = 117.35(3)° and R = 0.070, R_w = 0.050. 3 crystallizes in the monoclinic system, space group P2₁/c with a = 8.42(1), b = 20.808(9), c = 12.615(4) Å, β = 102.95(5)° and R = 0.045, R_w = 0.039. 4crystallizes in the triclinic system, space group P1, with a = 10.253(3), b = 12.338(5), c = 8.072(4) Å, = 100.65(4), β = 101.93(3), γ = 87.82(3)° and R = 0.038, R_w = 0.036 . The magnetic properties of 1 and 2 indicate the presence of weak net antiferromagnetic exchange, as indicated by the presence of a low temperature maximum in χ_m (80 K (1), 65 K (2)), but the data do not fit the Bleaney-Bowers equation unless the exchange integral is treated as a temperature dependent term. A similar situation has been observed for other related compounds, and various approaches to the problem will be discussed. Magnetically 3 and 4 are well described by the Bleaney-Bowers equation, exhibiting very strong antiferromagnetic exchange (− 2J = 768(24) cm⁻¹ (3); − 2J = 829(11) cm⁻¹ (4)).     

盐穗木金属硫蛋白HcMT的体外自由基清除活性及抗氧化能力*

目的: 原核表达盐穗木(Halostachys caspica C. A. Mey.)金属硫蛋白HcMT并探究其抗氧化活性。方法: 构建原核表达载体pET-32a-HcMT,转化至大肠杆菌Escherichia coli BL21,加入Zn²⁺胁迫培养(终浓度为200 μmol/L),分离纯化得到Zn-HcMT,测定Zn-HcMT自由基清除活性和总抗氧化能力,制备复合物Zn-HcMT/TiO₂并做FTIR表征。结果: 通过原核表达获得融合蛋白Zn-HcMT,对·OH、O₂·^-、DPPH自由基具有较强的清除活性,对·OH、O₂·^-的IC₅₀分别为0.386 mg/mL、0.038 mg/mL。融合蛋白浓度为0.01 mg/mL时,对DPPH清除率达(37.43 ± 0.006 8)%,浓度为0.3mg/mL时TEAC(trolox-equivalent antioxidant capacity)值为(1.023 ± 0.01)mmol/L,融合蛋白还原力A₇₀₀为0.142 ± 0.055,FTIR图谱同时表现了Zn-HcMT和TiO₂吸收特性。结论: Zn-HcMT具有良好的清除ROS活性及较强的抗氧化能力,在化妆品领域有潜在应用前景。     

Responses of soil respiration with biocrust cover to water and temperature in the southeastern edge of Tengger Desert,Northwest China

Aims Soil respiration of the lands covered by biocrusts is an important component in the carbon cycle of arid, semi-arid and dry-subhumid ecosystems (drylands hereafter), and one of the key processes in the carbon cycle of drylands. However, the responses of the rate of soil respiration with biocrusts to water and temperature are uncertain in the investigations of the effects of experimental warming and precipitation patterns on CO₂ fluxes in biocrust dominated ecosystems. The objectives of this study were to investigate the relationships of carbon release from the biocrust-soil systems with water and temperature in drylands. Methods Intact soil columns with two types of biocrusts, including moss and algae-lichen crusts, were collected in a natural vegetation area in the southeastern fringe of the Tengger Desert. Open top chambers were used to simulate climate warming, and the soil respiration rate was measured under warming and non-warming treatments using an automated soil respiration system (LI-8150). Important findings Over the whole observational period (from April 2016 to July 2016), soil respiration rates varied from -0.16 to 4.69 μmol·m^-2·s^-1 for the moss crust-covered soils and from -0.21 to 5.72 μmol·m^-2·s^-1 for the algae-lichen crust-covered soils, respectively, under different rainfall events (the precipitations between 0.3-30.0 mm). The mean soil respiration rate of the moss crust-covered soils is 1.09 μmol·m^-2·s^-1, which is higher than that of the algae-lichen crust-covered soils of 0.94 μmol·m^-2·s^-1. The soil respiration rate of the two types of biocrust-covered soils showed different dynamics and spatial heterogeneities with rainfall events, and were positively correlated with precipitation. The mean soil respiration rate of the biocrust-covered soils without warming was 1.24 μmol·m^-2·s^-1, significantly higher than that with warming treatments of 0.79 μmol·m^-2·s^-1 (p < 0.05). By increasing the evaporation of soil moisture, the simulated warming impeded soil respiration. In most cases, soil temperature and soil respiration rate displayed a similar single-peak curve during the diel cycle. Our results show an approximately two hours’ lag between soil temperature at 5 cm depth and the soil respiration rate of the biocrust-covered soils during the diel cycle.