Antifouling Activity of Bacterial Symbionts of Seagrasses against Marine Biofilm-Forming Bacteria

Marine biofouling has been regarded as a serious problem in the marine environment. The application of TBT and other heavy metal-based antifoulants has created another environmental problem. The present study explored the possible role of baterial symbionts of seagrasses Thalassia hemprichii, and Enhalus acoroides, which were successfully screened for antifouling activity against marine biofilm-forming bacteria isolated from the surrounding colonies of seagrasses. Bacterial symbionts were isolated and tested against biofilm-forming bacteria resulted in 4 bacterial symbionts capable of inhibiting the growth biofilm-forming isolates. Molecular identification based on 16S rRNA gene sequences revealed that the active bacterial symbionts belonged to the members of the genera Bacillus and Virgibacillus. Further tests of the crude extracts of the active bacterial symbionts supported the potential of these symbionts as the alternative source of environmentally friendly marine antifoulants.

The Nitrogen-Cycling Network of Bacterial Symbionts in the Sponge Spheciospongia vesparium

The microbes associated with sponges play important roles in the nitrogen cycle of the coral reefs ecosystem,e.g.,nitrification,denitrification,and nitrogen fixation.However,the whole nitrogen-cycling network has remained incomplete in any individual sponge holobiont.In this study,454 pyrosequencing of the 16S rRNA genes revealed that the sponge Spheciospongia vesparium from the South China Sea has a unique bacterial community(including 12 bacterial phyla),dominated particularly by the genus Shewanella(order Alteromonadales).A total of 10 functional genes,nifH,amoA,narG,napA,nirK,norB,nosZ,ureC,nrfA,and gltB,were detected in the microbiome of the sponge S.vesparium by gene-targeted analysis,revealing an almost complete nitrogen-cycling network in this sponge.Particularly,bacterial urea utilization and the whole denitrification pathway were highlighted.MEGAN analysis suggests that Proteobacteria(e.g.,Shewanella)and Bacteroidetes(e.g.,Bizionia)are probably involved in the nitrogen cycle in the sponge S.vesparium.

Growth response of Pterocarpus santalinus seedlings to native microbial symbionts(arbuscular mycorrhizal fungi and Rhizobium aegyptiacum)under nursery conditions

The objective of this research was to improve the growth and biomass of Pterocarpus santalinus L.f.(an endangered leguminous tree)using native microbial symbionts such as arbuscular mycorrhizal fungi and Rhizobium associated with native populations of P.santalinus.The native arbuscular mycorrhizal fungi isolated from P.santalinus soils were identifi ed as(1)Glomus fasciculatum;(2)Glomus geosporum;and Glomus aggregatum.A nitrogenfi xing microbial symbiont was isolated from the root nodules of P.santalinus and identifi ed as Rhizobium aegyptiacum by 16s rRNA gene sequencing.These microbial symbionts were inoculated individually and in combination into P.santalinus seedling roots.After 90 days,growth and biomass had improved compared with uninoculated controls.Shoot and root lengths,number of leaves,stem circumference,number of root nodules,biomass,nutrient uptake and seedling quality index were signifi cantly increased by a combined inoculation of arbuscular mycorrhizal fungi+Rhizobium aegyptiacum.It was concluded that native microbial symbionts positively infl uenced P.santalinus seedling growth which will be helpful for successful fi eld establishment.

Construction of a Metagenomic DNA Library of Sponge Symbionts and Screening of Antibacterial Metabolites

为了学习简历，活跃代谢物由导出海绵的未耕作的共生者生产了，海绵 Gelliodes gracilis 的共生者的一个 metagenomic DNA 图书馆被构造。DNA 的平均尺寸在图书馆插入是 20kb。这个图书馆用纸圆盘 assaying 为抗菌素活动被屏蔽。二克隆对小球菌 tetragenus 显示了抗菌剂活动。这二克隆的代谢物通过 HPLC 被分析。结果证明他们的代谢物与主人 E 的那些相当不同。包含向量 pHZ132 的关口 i DH5 α和主人。这研究可以介绍一条新途径给探索简历海绵共生者的活跃代谢物。

A bacterial symbiont in the gill of the marine scallop Argopecten irradians irradians metabolizes dimethylsulfoniopropionate

Microbial lysis of dimethylsulfoniopropionate(DMSP)is a key step in marine organic sulfur cycling and has been recently demonstrated to play an important role in mediating interactions between bacteria,algae,and zooplankton.To date,microbes that have been found to lyse DMSP are largely confined to free‐living and surface‐attached bacteria.In this study,we report for the first time that a symbiont(termed“Rhodobiaceae bacterium HWgs001”)in the gill of the marine scallop Argopecten irradians irradians can lyse and metabolize DMSP.Analysis of 16S rRNA gene sequences suggested that HWgs001 accounted for up to 93%of the gill microbiota.Microscopic observations suggested that HWgs001 lived within the gill tissue.Unlike symbionts of other bivalves,HWgs001 belongs to Alphaproteobacteria rather than Gammaproteobacteria,and no genes for carbon fixation were identified in its small genome.Moreover,HWgs001 was found to possess a dddP gene,responsible for the lysis of DMSP to acrylate.The enzymatic activity of dddP was confirmed using the heterologous expression,and in situ transcription of the gene in scallop gill tissues was demonstrated using reverse‐transcription PCR.Together,these results revealed a taxonomically and functionally unique symbiont,which represents the first‐documented DMSP‐metabolizing symbiont likely to play significant roles in coastal marine ecosystems.

Temporal changes of symbiont density and host fitness after rifampicin treatment in a whitefly of the Bemisia tabaci species complex

Microbial symbionts are essential or important partners to phloem-feeding insects. Antibiotics have been used to selectively eliminate symbionts from their host insects and establish host lines with or without certain symbionts for investigating functions of the symbionts. In this study, using the antibiotic rifampicin we attempted to selectively eliminate certain symbionts from a population of the Middle East-Asia Minor 1 whitefly of the Bemisia tabaci species complex, which harbors the primary symbiont ＂Candidatus Portiera aleyrodidarum＂ and two secondary symbionts ＂Candidatus Hamiltonella defensa＂ and Rickettsia. Neither the primary nor the secondary symbionts were completely depleted in the adults （F0） that fed for 48 h on a diet treated with rifampicin at concentrations of 1 100/zg/mL. However, both the primary and secondary symbionts were nearly completely depleted in the offspring （F 1） of the rifampicin-treated adults. Although the F1 adults produced some eggs （F2）, most of the eggs failed to hatch and none of them reached the second instar, and consequently the rifampicin-treated whitefly colony vanished at the F2 generation. Interestingly, quantitative polymerase chain reaction assays showed that in the rifampicin-treated whiteflies, the density of the primary symbiont was reduced at an obviously slower pace than the secondary symbionts. Mating experiments between rifampicin-treated and untreated adults demonstrated that the negative effects ofrifampicin on host fitness were expressed when the females were treated by the antibiotic, and whether males were treated or not by the antibiotic had little contribution to the negative effects. These observations indicate that with this whitefly population it is not feasible to selectively eliminate the secondary symbionts using rifampicin without affecting the primary symbiont and establish host lines for experimental studies. However, the extinction of the whitefly colony at the second generation after rifampicin treatment indicates the potential of the antibiotic as a control agent of the whitefly pest.

Consequences of coinfection with protective symbionts on the host phenotype and symbiont titres in the pea aphid system

Symbiotic associations between microbes and insects are widespread, and it is frequent that several symbionts share the same host individual. Hence, interactions can occur between these symbionts, influencing their respective abundance within the host with consequences on its phenotype. Here, we investigate the effects of multiple infections in the pea aphid, Acyrthosiphon pisurn, which is the host of an obligatory and several facultative symbionts. In particular, we study the influence of a coinfection with 2 protective symbionts： Harniltonella defensa, which confers protection against parasitoids, and Rickettsiella viridis, which provides protection against fungal pathogens and predators. The effects of Hamiltonella-Rickettsiella coinfection on the respective abundance of the symbionts, host fitness and efficacy of enemy protection were studied. Asymmetrical interactions between the 2 protective symbionts have been found： when they coinfect the same aphid individuals, the Rickettsiella infection affected Hamiltonella abundance within hosts but not the Hamiltonella-mediated protective phenotype while the Hamiltonella infection negatively influences the Rickettsiella-mediated protective phenotype but not its abundance. Harboring the 2 protective symbionts also reduced the survival and fecundity of host individuals. Overall, this work highlights the effects of multiple infections on symbiont abundances and host traits that are likely to impact the maintenance of the symbiotic associations in natural habitats.

Fungal symbionts of marine sponges from Rameswaram,southern India:species composition and bioactive metabolites

Ten marine sponge species from Rameswaram,southern India were studied for their filamentous fungal symbionts.The results suggest that fungal symbionts of marine sponges are hyperdiverse.Genera such as Acremonium,Alternaria,Aspergillus,Cladosporium,Fusarium and Penicillium were frequently isolated;no true marine fungal species were present.Species of Aspergillus were dominant and co-dominant in all the sponges screened.The fungal isolates produced antialgal,antifungal,antioxidant,antibiotic,antiinsect metabolites.A few fungi produced acetylcholinesterase inhibitors.

黑蚱蝉胚胎发育和幼期形态变化

【目的】本研究旨在揭示黑蚱蝉Cryptotympana atrata胚胎期的发育过程和共生菌在胚胎中的分布,确定若虫龄期数,明晰相关器官的形态发生过程以及若虫的形态变化(分化)与生境和寄主植物营养条件的相关性。【方法】通过野外采集和实验室人工饲养获得黑蚱蝉各发育阶段样本,采用光学显微镜和电子显微镜观察胚胎的发育,测量、分析不同龄期若虫的形态变化。【结果】黑蚱蝉的卵为长条形,表面具网状纹饰,卵孔位于距后极约1/4处。在胚胎发育初期,共生细菌Candidatus Sulcia muelleri(Sulcia)和类酵母共生真菌(yeast-like fungal symbionts, YLS)在卵的后极呈球状聚集;胚胎发育至约72 h后,新形成的胚带逐渐陷入卵黄中发育,共生菌球逐渐移动至前极,并进入附近宿主细胞;腹部分节后,共生菌球定殖于第6-8腹节背侧。发育至约第55天时进入滞育状态越冬,滞育期约为130 d。在胚胎发育早期,上唇节附肢从基部逐渐愈合,并与前唇基愈合形成复合结构。上颚节附肢不断延伸,形成上颚口针;下颚节附肢在胚胎发育早期即分化为外侧和内侧两个凸起,随后分别发育为近端的下颚板(后来又逐渐消失)和远端的口针。下唇节附肢在胚胎发育早期成对存在,之后愈合为一体,发育为喙管。发育至约第200天时,在第1腹节两侧出现胚足带,但发育至约第210天时随着胚胎翻转而逐渐退化。前若虫头部无齿突,胸、腹部具大量齿突,有助虫体破壳孵化;发育至约第245天时,一些胚胎开始孵化。若虫有5个龄期,各龄期除虫体不断增长外,复眼、触角、翅芽、胸足、生殖节等发生一系列形态变化,尤其是3对胸足的形态和功能分化最为显著。中足和后足细长,适于支撑和平衡身体;前足粗壮,腿节宽扁并逐渐形成齿梳,胫节镰刀状,具端齿、副齿和中叶,适于挖掘隧洞和固定于植物根系上取食。此外,1-4龄若虫均出现腹部膨大(Ⅰ型)和不膨大(Ⅱ型)两种类型个体,但5龄若虫无明显形态分化;以长势旺盛寄主植物柳树Salix babylonica和紫花苜蓿Medicago sativa为食的1龄若虫腹部形态分化早,以长势较差寄主为食的1龄若虫形态分化较迟,腹部不膨大个体比膨大个体进入2龄更早,且进入2龄后最初均为不膨大型个体。【结论】在黑蚱蝉胚胎发育过程中,由Sulcia和YLS组成的共生菌球从卵的后极移动至前极,最后定殖于第6-8腹节;上颚口针为基颚突起源,下颚口针为端颚突起源;黑蚱蝉若虫具5个龄期,幼期阶段的形态(功能)特化与其长期在地下隐蔽生活及羽化后的生态位转变密切相关,并与寄主植物的营养供给条件相关。

不同地理种群中各个体红火蚁肠道细菌多样性分析

昆虫体内普遍存在共生菌,这些共生菌需稳定定殖于昆虫体内才能与昆虫建立稳定的互作关系。为明确红火蚁Solenopsis invicta的共生菌种类与组成,本研究通过16s rRNA扩增子测序,对不同地理种群中红火蚁体内细菌群落进行比较。结果显示红火蚁工蚁与有翅雌蚁肠道细菌组成对环境敏感,不同地理种群间差异较大,幼虫共生菌组成种类相对保守,其中肠球菌Enterococcus为第一优势菌。该研究结果表明红火蚁幼虫肠道细菌组成稳定,而工蚁与有翅蚁无常驻共生菌,未来可从重点关注幼虫体内共生菌功能及其与红火蚁间的相互作用机制。

电场预处理对藻菌共生体处理养猪废水的影响机制分析

随着畜禽养殖业规模化集约化的发展,畜禽养殖废水已经成为了农业面源污染的主要来源,但其自身包含大量碳氮磷等营养元素又是重要的农业资源。针对养猪废水高色度浊度、高碳氮磷的特点,引入电场预处理来降低废水的色度、浊度,在促进藻菌共生体生长的同时提高废水中污染物的去除效率。结果表明:电场预处理能使养猪废水中的色度、浊度得到有效降低,铁、铝做阳极时色度、浊度的去除率均能达到90%以上。经电场预处理的废水在藻菌共生体的培养上也有更优的表现,铁、铝做阳极组中藻菌共生体对COD、TN、TP的7 d去除率分别为59.09%、61.78%、68.96%和62.26%、62.26%、83.92%,优于未经电场预处理组的47.82%、59.3%、60.48%。此外,铁、铝做阳极组和未经电场预处理组叶绿素含量分别从7.63、7.32、7.37 mg·L^(-1),增长到24.39、26.08、12.98 mg·L^(-1),是接种时的3.20、3.54、1.70倍,电场预处理明显提高了藻菌共生体中叶绿素的含量。说明电场预处理能有效提升藻菌共生体对污染物的去除效果,并获得更大的生物质资源,同步实现对废水的深度处理和资源利用。

Impact of a novel Rickettsia symbiont on the life history and virus transmission capacity of its host whitefly(Bemisia tabaci)

Rickettsia consists of some of the most prevalent symbionts of insects and often plays a significant role in the biology of its hosts.Recently,a maternally inherited Torix group Rickettsia,provisionally named as RiTBt,was recorded in a species of notorious pest whitefly,tentatively named as Asia II 1,from the Bemisia tabaci complex.The role of this Rickettsia in the biology of its host is unknown.Here we investigated the impact of RiTBt on the performance and virus transmission capacity of Asia II 1.RiTBt did not significantly affect the life history parameters of the whitefly when the host insect was reared on tobacco,tomato,and cotton,three host plants with relatively low,medium and high suitability to the whitefly.Intriguingly,RiTBt slightly enhanced whitefly transmission of cotton leaf curl Multan virus(CLCuMuV),a virus that is transmitted by the whitefly in the field and has caused extensive damage to cotton production.Specifically,compared with whiteflies without RiTBt,following a 48 h virus acquisition whiteflies with RiTBt had higher titer of virus and showed higher efficiency of virus transmission.A rickettsial secretory protein BtR242 was identified as a putative virus-binding protein,and was observed to interact with the coat protein of CLCuMuV in vitro.Viral infection of the whitefly downregulated gene transcript levels of the BtR242 gene.These observations indicate that RiTBt has limited impact on the biology of the Asia II 1 whitefly,and whether this symbiont has functions in the biology of other host whiteflies warrants future investigation.

Genomic and transcriptomic analyses reveal metabolic complementarity between whiteflies and their symbionts

Nutritional mutualism between insects and symbiotic bacteria is widespread.The various sap-feeding whitefly species within the Bemisia tabaci complex associate with the same obligate symbiont(Portiera)and multiple secondary symbionts.It is often assumed that some of the symbionts residing in the whiteflies play crucial roles in the nutritional physiology of their insect hosts.Although effort has been made to understand the functions of the whitefly symbionts,the metabolic complementarity offered by these symbionts to the hosts is not yet well understood.We examined two secondary symbionts,Arsenophonus and Wolbachia,in two species of the B.tabaci whitefly complex,provisionally named as Asia II 3 and China 1.Genomic sequence analyses revealed that Arsenophonus and Wolbachia retained genes responsible for the biosynthesis of B vitamins.We then conducted transcriptomic surveys of the bacteriomes in these two species of whiteflies together with that in another species named MED of this whitefly complex previously reported.The analyses indicated that several key genes in B vitamin syntheses from the three whitefly species were identical.Our findings suggest that,similar to another secondary symbiont Hamiltonella,Arsenophonus and Wolbachia function in the nutrient provision of host whiteflies.Although phylogenetically distant species of symbionts are associated with their respective hosts,they have evolved and retained similar functions in biosynthesis of some B vitamins.Such metabolic complementarity between whiteflies and symbionts represents an important feature of their coevolution.

Hosting certain facultative symbionts modulates the phenoloxidase activity and immune response of the pea aphid Acyrthosiphon pisum

The pea aphid Acyrthosiphon pisum hosts different facultative symbionts(FS)which provide it with various benefits,such as tolerance to heat or protection against natural enemies(e.g.,fungi,parasitoid wasps).Here,we investigated whether and how the presence of certain FS could affect phenoloxidase(PO)activity,a key component of insect innate immunity,under normal and stressed conditions.For this,we used clones of A.pisum of difTerent genetic backgrounds(LLOl,YR2 and T3-8V1)lacking FS or harboring one or two(Regiella insecticola,Hamiltonella defensa,Serratia symbiotica Rickettsiella viridis).Gene expression and proteomics analyses of the aphid hemolymph indicated that the two A.pisum POs,PPOl and PP02,are expressed and translated into proteins.The level of PPO genes expression as well as the amount of PPO proteins and phenoloxidase activity in the hemolymph depended on both the aphid genotype and FS species.In particular,H.defensa and R.insecticola,but not S.symbiotica-h R.viridis,caused a sharp decrease in PO activity by interfering with both transcription and translation.The microinjection of different types of stressors(yeast,Escherichia coli,latex beads)in the YR2 lines hosting different symbionts affected the survival rate of aphids and,in most cases,also decreased the expression of PPO genes after 24 h.The amount and activity of PPO proteins varied according to the type of FS and stressor,without clear corresponding changes in gene expression.These data demonstrate that the presence of certain FS influences an important component of pea aphid immunity.

The fly factor phenomenon is mediated by interkingdom signaling between bacterial symbionts and their blow fly hosts

We tested the recent hypothesis that the"fly factor"phenomenon(food cur-rently or previously fed on by flies attracts more flies than the same type of food kept inccessible to flies)is mediated by bacterial symbionts deposited with feees or regur-gitated by feeding flies.We allowed laboratory-reared black blow flies,Phormia regina(Meigen),to feed and de fecate on bacterial Luria-Bertani medium solidified with agar,and isolated seven morphologically distinct bacterial colonies.We identified these us-ing matrix-assisted laser desorption/ionization mass spectrometry and sequencing of the 165 rRNA gene.In two-choice laboratory experiments,traps baited with cultures of Pro-teus mirabilis Hauser,Morganella morganii subsp.sibonii Jensen,or Serratia marcescens Bizio,captured significantly more flies than corresponding control jars baited with tryptic soy agar only.A mixture of seven bacterial strains as a trap bait was more attractive to flies than a single bacterial isolate(M.m.siboni).In a field experiment,traps baited with agar cultures of P:mirabilis and M.m siboni in combination captured significantly more flies than lraps baited with either bacterial isolate alone or the agar control.As evident by gas chromatography-mass spectrometry,the odor profiles of bacterial isolates differ,which may explain the additive effect of bacteria to the attractiveness of bacterial trap baits.As"generalist bacteria,"P mirabilis and M.m.sibonii growing on animal protein(beef liver)or plant protein(tofu)are similarly effective in attracting flies.Bacteria-derived airborne semiochemicals appear to mediate foraging by flies and to inform their feeding and oviposition decisions.

Symbionts, a promising source of bioactive natural products

Symbionts are microorganisms residing in multicellular hosts(e.g., plants and animals), and they have been witnessed to be a rich source of diverse functional molecules. This review describes structures and biological activities of symbiont-derived secondary metabolites commonly referred to as "natural products", and highlights that symbiotic microbes represent an underexplored reservoir of natural products with unique scaffolds and promising significance in managing human healthcare and agricultural production.

芽孢杆菌的引入对褐飞虱微生物群和生长发育的影响

【目的】明确褐飞虱Nilaparvata lugens体内可培养共生细菌的种类,探索其中芽孢杆菌类共生菌对褐飞虱微生物群和生长发育的影响。【方法】通过离体培养的方法,从褐飞虱两种不同致害性种群(TN1敏感种群和IR56高致害种群)中分离可培养共生细菌。通过16S rDNA测序对获得的可培养共生菌进行鉴定,在此基础上利用原位杂交研究了共生细菌在褐飞虱体内的分布。利用人工饲料添加抗生素和回补共生细菌的方式,研究了减菌和回补芽孢杆菌的处理对褐飞虱生长发育以及共生菌丰度的影响。比较了通过饲喂和显微注射对芽孢杆菌引入的影响,考察了芽孢杆菌的定殖与褐飞虱TN1种群致害性之间的相关性。【结果】利用离体培养法从褐飞虱中获得了15株不同的共生细菌,其中包括2株源于IR56高致害种群的芽孢杆菌类共生细菌BPH-S36和BPH-S33。原位杂交结果表明共生细菌在褐飞虱成虫唾液腺、肠道、脂肪体和雌虫内生殖器中均有分布,而在雄虫内生殖器中鲜有分布。体内共生细菌对褐飞虱的生长发育至关重要,共生细菌的减少导致褐飞虱存活率在第3和6天时显著下降,而回补共生芽孢杆菌BPH-S36或BPH-S33可使其存活率在第6天时显著上升。褐飞虱通过取食添加共生芽孢杆菌的人工饲料可使芽孢杆菌的相对丰度增加23.2~24.5倍,而通过若虫显微注射并不能够提高芽孢杆菌的相对丰度。随着共生芽孢杆菌的增加,类酵母共生菌(yeast-like symbiont,YLS)的相对丰度也显著增加5~12倍。芽孢杆菌BPH-S36的引入使褐飞虱敏感种群TN1在抗性水稻IR56上的存活率由52.1%±1.5%显著提高至64.2%±3.0%。【结论】共生细菌在褐飞虱唾液腺、肠道和卵巢中广泛分布。抗生素处理能够有效降低其体内共生细菌的丰度,从而导致存活率下降。人工饲喂法可以使外源共生细菌在褐飞虱体内成功定殖。源于致害性强的褐飞虱种群中的芽孢杆菌BPH-S36可提高该种群对抗性水稻品种IR56的致害性。

光臀八齿小蠹共生微生物群落组成及其功能基因注释

【目的】揭示光臀八齿小蠹Ips nitidus共生微生物群落组成和功能特征。【方法】对来自中国西北部青海省麦秀自然保护区的光臀八齿小蠹进行肠道和其他组织共生真菌和细菌宏基因组学和相关性网络分析,比较光臀八齿小蠹肠道和其他组织共生真菌及细菌群落组成,分析微生物群落间的相互关系,并采用非冗余蛋白序列比对方法注释共生微生物功能基因。【结果】共发现光臀八齿小蠹肠道和其他组织共生微生物3520种,真菌和细菌的物种数最高,分别占全部物种数的23.21%和69.01%,平均相对丰度分别为9.69%和13.79%。其他组织中共生真菌白粉菌目(Erysiphales)相对丰度和物种多样性较肠道中的高,而其他组织中酵母目(Saccharomycetales)相对丰度和物种多样性较肠道中的低;其他组织中长喙壳类真菌(ophiostomatoid fungi)多样性(6属16种)较在肠道中的(5属13种)高,在其他组织和肠道中的平均相对丰度分别为0.016%和0.013%。其他组织中肠杆菌目(Enterobacterales)相对丰度和物种多样性高于肠道中的。肠杆菌属Enterobacter、白粉菌属Erysiphe、丛枝菌根属Rhizophagus和沃尔巴克氏菌属Wolbachia均为肠道和其他组织的核心菌属。真菌和细菌的某些群落在肠道和其他组织间表现出相反的相互关系,表明光臀八齿小蠹共生菌间可能存在复杂的相互作用。分别鉴定到共生真菌和细菌功能基因7010和6483个,细菌中异源性物质生物降解和代谢相关功能基因数量远高于真菌的;mRNA监测通路、丙酸代谢和泛素介导的蛋白质水解等11条通路在肠道中较在其他组织中具有更多的差异基因;对于柠檬烯降解和甾醇合成相关功能基因的注释结果表明,细菌对柠檬烯较真菌具有明显的降解能力,而真菌在甾醇生物合成中较细菌发挥更重要的促进作用;74个长喙壳类真菌功能基因主要参与到氧化磷酸化、代谢通路和氨基酸代谢,且长喙壳类真菌在其他组织中多样性更高,主要分布于Ophiostoma等。【结论】光臀八齿小蠹肠道和其他组织中共生微生物的群落组成和多样性以及功能上存在一定的差异性,肠杆菌属、白粉菌属、丛枝菌根属和沃尔巴克氏菌属是光臀八齿小蠹共生微生物群落中最重要的核心菌群,可能在群落构建中发挥着重要的作用。

昆虫共生微生物:研究进展与展望

昆虫共生微生物是指与昆虫宿主建立持久互作关系的微生物,这些微生物分布于昆虫的体表、肠道、血腔或者细胞内,参与调节宿主昆虫的多种生理功能。昆虫-共生微生物互作研究涉及多个学科领域的交叉。深入研究昆虫共生微生物的功能及其与宿主的互作关系不仅有助于阐明重要的生命科学机理,还将为害虫治理和虫传病害的防控以及益虫的有效利用提供新的思路和方法。近年来,我国学者在昆虫微生物组研究领域取得显著进展,在多个研究方向取得重要成果。本文概述了国内外昆虫共生微生物研究的最新进展,介绍了本专辑论文的主要研究内容,并提出了值得关注的3个研究方向:(1)昆虫细胞内共生微生物的功能;(2)昆虫调控共生微生物丰度和传播的机制;(3)昆虫共生微生物的遗传改造和应用。

职业教育产教融合共生体的发展困境及推进策略研究——基于共生理论的视角

职业教育的深度产教融合强调共生体的建设。在职业教育迈向高质量发展阶段,加强对职业教育产教融合共生体的研究,有利于深化对共生体利益相关者之间融合关系的认识,促进产教融合多元机制的形成,推动现代职业教育体系的完善,助力职业教育实现培养高素质技术技能人才的目标。基于共生理论的视角,职业教育产教融合共生体包含政府部门、行业组织、企业和职业院校等核心共生主体;存在不同的共生模式,其中最理想的组织共生模式是一体化共生,最理想的行为共生模式是对称性互惠共生;职业教育产教融合共生体建设需要有法制、宏观制度和文化环境的保障。目前职业教育产教融合共生体建设处于初级阶段,共生主体地位不平等,多元协同共治局面尚未完全形成;共生模式不够理想,未形成一体化与互惠共生的模式;制度不健全与文化环境偏差,不利于各主体共生关系的建立。完善职业教育产教融合的共生体建设,需从机制、模式和环境三个维度入手,确保主体平等地位,实现多元协同共治共生局面,强化产教融合一体化共生及利益的平等共享,并营建有助于产教融合共生体建设的职教环境。