产油微生物利用餐厨垃圾生产油脂的研究进展

餐厨垃圾中含有丰富的营养物质,经生物转化过程可以合成对人类有用的化学品。某些产油微生物可以处理餐厨垃圾生产油脂,同时合成高附加值代谢产物如多不饱和脂肪酸、角鲨烯和类胡萝卜素等。这不仅能够降低生产成本,而且提高了产物的经济价值,具有极大的工业化应用潜力。文中主要概括了目前餐厨垃圾的处理研究现状,综述了产油微生物发酵餐厨垃圾生产油脂的研究进展,并结合笔者的工作对未来该领域的发展进行了总结与展望,以期为今后的相关研究提供有益借鉴。     

餐厨垃圾资源化利用技术研究现状及展望

餐厨垃圾产生量大、成分复杂、具有"危害性"和"资源性"的双重属性,随着垃圾分类工作的推进,将餐厨垃圾作为一种生物资源回收其中的资源和能源的研究受到了越来越多的关注。本文介绍了餐厨垃圾的成分特性及预分选方法,对餐厨垃圾厌氧消化、好氧堆肥、生物饲料、昆虫养殖、热处理技术及生物炼制生产高附加值化学品等主要的资源化利用途径进行了分析,并对餐厨垃圾收集及资源化过程中产生的恶臭气体、废水污染问题及处理方法进行了介绍。最后指出餐厨垃圾厌氧消化、昆虫养殖、好氧堆肥及生物饲料技术工业化利用过程中的设备运行的稳定性及其废水和臭气的控制问题仍需进一步的研究。餐厨垃圾热处理过程如何进一步降低能耗及开发高附加值的功能炭材料是未来的重要发展方向,餐厨垃圾生物炼制生产高附加值化学品是实现餐厨垃圾高值化利用的有效途径,也是替代传统化工路线生产化学品的重要路径。总之,采用多技术耦合是实现餐厨垃圾"减量化、无害化、资源化"的有效手段,也是发展我国循环经济发展的必然要求。     

餐厨垃圾厌氧消化处理主要过程的微生物群落结构分析

【背景】厌氧消化是我国餐厨垃圾处理的主要方法,微生物在其处理过程中起到关键作用,但是目前对其不同工艺单元微生物群落结构的研究较少。【目的】通过分析各工艺单元的微生物多样性与群落结构,为改进餐厨垃圾资源化处理技术、提高资源利用效率提供科学依据。【方法】采集某餐厨垃圾处理厂油水分离、厌氧发酵、沼渣脱水等3个工艺单元产生的废液样品,采用16S rRNA基因高通量测序技术,研究其菌群组成、丰度、优势菌群及其与环境因子的相关性。【结果】初始油水分离样品中的微生物群落种类相对较少,而经厌氧发酵和沼渣脱水处理后样品中的微生物群落种类较丰富。在门水平上,厚壁菌门(Firmicutes)在各单元样品中所占平均比例最高,为81.1%,其次为拟杆菌门(Bacteroidetes)和绿弯菌门(Chloroflexi),分别占15.81%和4.59%;在属水平上,相对丰度较高的菌属为乳酸菌属(Lactobacillus)、互营单胞菌属(Syntrophomonas)等。餐厨垃圾处理过程中的部分菌属可能具有资源-环境双重属性,例如在沼渣脱水单元相对丰度高达32.67%的假单胞菌属(Pseudomonas),该菌属中既存在少部分致病菌或条件致病菌,也具有生产聚羟基脂肪酸酯的功能菌。影响各组样品微生物群落组成结构最显著的因子是p H值,其次是总糖的含量。【结论】研究明确了典型餐厨垃圾厌氧消化处理工艺单元的微生物群落结构和多样性,并提出了优化处理工艺、强化资源利用效率的建议。     

不同投料方式对黑水虻幼虫生长性能的影响

以获得黑水虻Hermetia illucens转化有机废弃物的养殖投喂工艺参数为目标,采用实验室小试模拟试验,以餐厨垃圾为试验原料,研究不同投料方式（1次、2次、3次和4次投料）对黑水虻转化餐厨垃圾过程中幼虫生长性能的影响。结果表明,采用多次投料方式,随着投料次数增加,对转化物料料温波动影响较大,不利于幼虫快速生长;在投虫量和投料量相同条件下,养殖周期为10 d,其中以1次投料处理组的收虫体重、体长、单位面积虫产量为最高,料虫比为最低,与2次投料差异不显著（P＞0.05）,但与3次、4次投料处理组差异显著（P＜0.05）;黑水虻转化废弃物前期较低的物料含水率更加有利于虫体生长,而后期物料含水率较高则更为有利。通过生产性能分析发现,从投料回报效果角度考虑生产性能以1次投料为最佳,而从高效率处理餐厨垃圾和投料回报效果两者角度综合分析,生产性能以2次投料为最佳。该结果可为构建黑水虻转化餐厨垃圾标准化生产工艺参数技术体系奠定基础。     

中国餐厨垃圾处理的现状、问题和对策

餐厨垃圾具有高水分、高盐分、高有机质含量、组分时空差异明显、危害性与资源性并存的特点。目前国内外常用的餐厨垃圾处理技术如焚烧、卫生填埋、生态饲料、厌氧消化、好氧堆肥和蚯蚓堆肥等,通常存在着资源化利用效率低、经济效益不够理想的缺陷。总结相关文献及报道,中国在餐厨垃圾资源化处理上存在"行政瓶颈"和"技术瓶颈"两大方面的问题:"行政瓶颈"的解决之道在于完善管理及处理体系,各级政府部门切实重视、加大投入,强力推进垃圾分类投放;而对于"技术瓶颈",除综合运用多种现有处理技术外,开发新技术提高餐厨垃圾的资源化循环利用程度,是关键所在。     

黑水虻幼虫处理餐厨垃圾过程中体内养分组成与消化酶活性变化规律的研究

黑水虻 Hermetia illucens 作为一种新型资源环境昆虫,其幼虫可以处理餐厨垃圾、畜禽粪便、蔬菜残体等各种有机废弃物。幼虫富含蛋白质和油脂,可以作为水产饲料的蛋白来源。本研究探索黑水虻幼虫处理餐厨垃圾过程中其养分组成与消化酶活性变化之间的关系。通过黑水虻幼虫自由取食餐厨垃圾,每日采集样品用于物质养分和消化酶活性的测定。结果显示：黑水虻幼虫粗蛋白含量呈现先下降后上升的变化规律,而幼虫总糖含量呈现先上升后下降的变化规律,粗脂肪含量维持上升的趋势。幼虫处理餐厨垃圾过程中,体内蛋白酶在初期迅速上升,第6天后逐渐下降,而淀粉酶呈现出先缓慢上升再迅速上升最后下降的变化规律。脂肪酶在黑水虻幼虫处理餐厨垃圾前期保持较高的活性然后缓慢下降。同时,通过相关性分析,黑水虻幼虫粗蛋白含量变化与蛋白酶活性没有相关性,而总糖与粗脂肪含量变化分别与淀粉酶、脂肪酶有相关性。因此,部分消化酶活性变化与黑水虻幼虫养分组成具有一定的联系,本研究结果为工厂化养殖黑水虻提供一定的理论基础。     

餐厨垃圾和市政污泥配料比对厌氧产甲烷特性及微生物多样性的影响

在(38±0.5)℃的温度下,研究不同配料比对餐厨垃圾和市政污泥混合厌氧消化过程中系统参数及微生物群落多样性的影响,设定餐厨垃圾和市政污泥的挥发性固体的质量比为1∶0、0∶1、1∶1、1∶2和2∶1,并采用高通量测序技术分析厌氧消化过程中微生物组成的多样性。结果表明:质量比为1∶1的体系混合厌氧消化时,产甲烷效果最佳,单位质量的挥发性固体含量的产甲烷量可达到232.86 L/kg,挥发性固体含量的去除率达46.09%。各个混合比例体系中的优势物种为拟杆菌门(Bacteroidetes)和甲烷八叠球菌属(Methanosarcina)。在餐厨垃圾中添加市政污泥混合厌氧消化能够提高微生物群落的多样性,促进菌种间的协同作用,进而提升产气效率。     

餐厨垃圾高温好氧生物减量菌种的筛选及特性

【背景】随着餐厨垃圾产生量的逐步提高,如何实现其快速降解,成为餐厨垃圾处理亟待解决的问题。餐厨垃圾的高温好氧生物减量技术是一种可以快速降解餐厨垃圾的有效方法。【目的】筛选能够适应餐厨垃圾环境且具有高效降解餐厨垃圾中有机物能力的菌株,以提高餐厨垃圾的降解效率和减量效果。【方法】采用温度梯度耐受性实验和餐厨垃圾浸出液高油高盐耐受性实验进行菌种初筛,并利用产酶培养基复筛及餐厨垃圾生物减量实验验证。【结果】通过初筛、复筛和功能验证,最终获得4株生物减量效果优良的菌株N3-1、C7、N3-3和G6-1,其对餐厨垃圾挥发性固体(volatile solid,VS)的降解率分别为36.95%、33.23%、32.83%和31.91%,是对照组的3.02、2.71、2.68和2.61倍。经鉴定,这4株菌分别属于热嗜油地芽孢杆菌(Geobacillus thermoleovorans)、史氏芽孢杆菌(Bacillus smithii)、热解木糖地芽孢杆菌(Geobacillus caldoxylosilyticus)和立陶宛地芽孢杆菌(Geobacillus lituanicus)。【结论】筛选出的4株菌均具有较强的餐厨垃圾原料适应性和高效的生物降解能力,为开发餐厨垃圾高温好氧复合菌剂奠定了基础,并为实现餐厨垃圾减量化、无害化处理和资源化利用提供了技术支持。     

园林废弃物堆肥化技术中微生物菌剂的功能与作用

园林废弃物的日益增加给环境带来了巨大压力。微生物菌剂接种于园林废弃物中堆肥,可以加速堆肥的腐熟度,增强肥效,改善并促进资源利用效率,在园林废弃物再利用方面已显示较好的应用前景。从园林废弃物目前的处理方法和菌剂在堆肥化技术方面的应用着手,介绍了微生物在园林废弃物堆腐中和发酵成微生物菌肥后的功能与作用,阐述了目前监测堆肥腐熟程度的重要参数以及检测发酵过程中菌群变化的技术手段,最后对微生物菌剂接种于园林废弃物堆肥化技术的前景进行了展望,旨为相关领域的研究与开发提供参考和借鉴。     

餐厨废弃物脱硫菌分离筛选与鉴定

为获得在餐厨废弃物堆肥过程中可以减少硫化氢排放的微生物。将餐厨废弃物堆肥进行富集,筛选及鉴定,初步判定菌属,将脱硫菌分别进行培养条件优化的单因素试验,以确定最佳除臭培养条件。结果显示,筛选出的两株脱硫菌分别为KW6和KSW8,KW6属于芽孢杆菌属,KSW8属于根瘤菌属。KW6在培养温度为30℃、pH为7.5、接种量为12%的时候硫化氢去除率最高,分别为83.5%、65.3%和73.8%;KSW8在培养温度为35℃时,pH为6.5、接种量为20%的时候硫化氢去除率最高,分别为85.8%、75.8%和72.4%。KW6和KSW8与CK相比分别使硫化氢释放量平均降低了28.83%和50.08%,KW6最佳除臭培养条件为温度30℃、pH为7.5、接种量为12%;KSW8最佳除臭培养条件为温度35℃、pH为6.5、接种量为20%。     

Process stability and microbial community structure in anaerobic hydrogen-producing microflora from food waste containing kimchi

Hydrogen production by the dark fermentation of food wastes is an economic and environmentally friendly technology to produce the clean energy source as well as to treat the problematic wastes. However, the long-term operations of the continuous anaerobic reactor for fermentative hydrogen production were frequently unstable. In this study, the structure of microbial community within the anaerobic reactor during unstable hydrogen production was examined by denaturing gradient gel electrophoresis (DGGE) and terminal restriction fragment length polymorphism (T-RFLP) techniques. The changes in microbial community from H(2)-producing Clostridium spp. to lactic acid-producing Lactobacillus spp. were well coincident with the unexpected process failures and the changes of metabolites concentrations in the effluent of the anaerobic reactor. As the rate of hydrogen production decreased, effluent lactic acid concentration increased. Low rate of hydrogen production and changes in microbial community were related to the 'kimchi' content and storage temperature of food waste feed solution. After low temperature control of the storage tank of the feed solution, any significant change in microbial community within the anaerobic reactor did not occur and the hydrogen production was very stably maintained for a long time.     

Biogas production and microbial community change during the Co-digestion of food waste with chinese silver grass in a single-stage anaerobic reactor

Chinese silver grass (CSG), a potential subtropical energy crop, was investigated as a co-substrate to enhance the anaerobic digestion of food waste for municipal solid waste treatment. Results showed that 88.1% of food wastes were degraded using CSG as a co-substrate with 45 days of digestion, where the food waste, CSG, and sludge on VS/TS/working volume was 93.14 g/111.55 g/1 L, in which the average biogas production was at 429.3 L/kg solids, and the average methane content was around 60%. During the digestion, the concentrations of ammonium and free ammonia gradually increased to 1448.2 and 265.2 mg/L respectively, without any significant inhibitory effects on biogas production, which is probably due to the buffering effects of CSG. Microbial community analysis showed that microorganisms from the class of Firmicutes and Bacteroidetes were dominant during digestion, and that the microbial community diversity increased with active methanogenesis, suggesting that the addition of substrates contribute to the increase of microbial diversity, and could be beneficial for biogas production. Therefore, using CSG as a co-substrate in the single-stage food waste anaerobic digestion system is a potential simple method to convert CSG into renewable energy and to simultaneously improve food waste treatment.     

Effect of Increasing Total Solids Contents on Anaerobic Digestion of Food Waste under Mesophilic Conditions: Performance and Microbial Characteristics Analysis

The total solids content of feedstocks affects the performances of anaerobic digestion and the change of total solids content will lead the change of microbial morphology in systems. In order to increase the efficiency of anaerobic digestion, it is necessary to understand the role of the total solids content on the behavior of the microbial communities involved in anaerobic digestion of organic matter from wet to dry technology. The performances of mesophilic anaerobic digestion of food waste with different total solids contents from 5% to 20% were compared and the microbial communities in reactors were investigated using 454 pyrosequencing technology. Three stable anaerobic digestion processes were achieved for food waste biodegradation and methane generation. Better performances mainly including volatile solids reduction and methane yield were obtained in the reactors with higher total solids content. Pyrosequencing results revealed significant shifts in bacterial community with increasing total solids contents. The proportion of phylum Chloroflexi decreased obviously with increasing total solids contents while other functional bacteria showed increasing trend. Methanosarcina absolutely dominated in archaeal communities in three reactors and the relative abundance of this group showed increasing trend with increasing total solids contents. These results revealed the effects of the total solids content on the performance parameters and the behavior of the microbial communities involved in the anaerobic digestion of food waste from wet to dry technologies.     

Biogas production by microbial communities via decomposition of cellulose and food waste

Several active microbial communities that form biogas via decomposition of cellulose and domestic food waste (DFW) were identified among 24 samples isolated from different natural and anthropogenic sources. The methane yield was 190–260 ml CH₄/g from microbial communities grown on cellulose substrates, office paper, and cardboard at 37°C without preprocessing. Under mesophilic conditions, bioconversion of paper waste yields biogas with a methane content from 47 to 63%; however, the rate of biogas production was 1.5–2.0 times lower than under thermophilic conditions. When microbial communities were grown on DFW under thermophilic conditions, the most stable and effective of them produced 230–353 ml CH₄/g, and the methane content in biogas was 54–58%. These results demonstrates the significance of our studies for the development of a technology for the biotransformation of paper waste into biogas and for the need of selection of microbial communities to improve the efficiency of the process.     

PLFA profiles for microbial community monitoring in anaerobic digestion

The use of municipal solid waste as feedstock for biogas production offers an interesting possibility for waste treatment with the beneficial effect of gaining a green energy source. The involved processes are very complex, and many different organisms connected via a dynamic food web are associated with them. These complex interactions within these microbial communities are still not clearly understood. Therefore, a phospholipid fatty acid (PLFA) profile analysis method, well established in aerobic but still not as common in anaerobic systems, was used to throw some light on this matter. In the present investigation, a 750 m3 biogas reactor (Roppen, Austria) was monitored over a half-year period. During this period, four different phases in terms of gas production could be determined: low (I), increasing (II), high (III), and decreasing (IV) gas production. In combination with the PLFA profiles, we were able to identify changes in the microbial community associated with these phases.     

废气处理生物滤器微生物生态学研究进展

废气生物处理是一项新兴的气体污染控制技术,已成为当前环境领域的研究热点.本文概述了生物滤器系统(包括生物过滤器系统和生物滴滤器系统)结构及其去除气体污染物的原理,重点阐述了生物滤器微生物的分离、鉴定及其降解特性,微生物丰度、活性与微生物群落结构多样性之间的相关性,运行条件对微生物群落的影响,微生物群落结构时空变化规律,生物膜形成机理和模型等方面的研究进展,并对今后废气处理生物滤器微生物生态学研究方向进行了展望.     

Volatile fatty acids (VFAs) and methane from food waste and cow slurry: Comparison of biogas and VFA fermentation processes

The potential of various biomasses for the production of green chemicals is currently one of the key topics in the field of the circular economy. Volatile fatty acids (VFAs) are intermediates in the methane formation pathway of anaerobic digestion and they can be produced in similar reactors as biogas to increase the productivity of a digestion plant, as VFAs have more varying end uses compared to biogas and methane. In this study, the aim was to assess the biogas and VFA production of food waste (FW) and cow slurry (CS) using the anaerobic biogas plant inoculum treating the corresponding substrates. The biogas and VFA production of both biomasses were studied in identical batch scale laboratory conditions while the process performance was assessed with chemical and microbial analyses. As a result, FW and CS were shown to have different chemical performances and microbial dynamics in both VFA and biogas processes. FW as a substrate showed higher yields in both processes (435 ml CH₄/g VS_fed and 434 mg VFA/g VS_fed) due to its characteristics (pH, organic composition, microbial communities), and thus, the vast volume of CS makes it also a relevant substrate for VFA and biogas production. In this study, VFA profiles were highly dependent on the substrate and inoculum characteristics, while orders Clostridiales and Lactobacillales were connected with high VFA and butyric acid production with FW as a substrate. In conclusion, anaerobic digestion supports the implementation of the waste management hierarchy as it enables the production of renewable green chemicals from both urban and rural waste materials.     

解淀粉乳酸细菌在L-乳酸发酵生产中的应用

对解淀粉乳酸细菌及其产生的淀粉酶和发酵工艺等方面的国内外研究现状进行了综述。解淀粉乳酸细菌具有分泌淀粉酶的能力,可免去原料水解处理工序直接发酵淀粉质原料生产乳酸,可以简化生产工艺,并可节约设备投资,进而降低生产成本。解淀粉乳酸细菌主要分离自传统发酵食品,也可从有机废弃物和厨余垃圾中分离得到。介绍了解淀粉乳酸细菌直接利用淀粉质原料的机理,比较了解淀粉乳酸菌发酵生产L-乳酸的工艺。提出通过诱变育种和基因工程育种等方法获得更加高效的解淀粉乳酸细菌,并结合先进的发酵、分离技术来提高乳酸生产效率。