Why do alpha-cyanobacteria with form 1A RuBisCO dominate aquatic habitats worldwide? (CYANORUB)

为什么具有 1A 型 RuBisCO 的 α-蓝藻在全世界的水生栖息地中占主导地位？

• 批准号: EP/Y028384/1
• 负责人: David Scanlan
• 金额: $ 23.84万
• 依托单位: University of Warwick
• 依托单位国家: 英国
• 项目类别: Fellowship
• 财政年份: 2024
• 资助国家: 英国
• 起止时间: 2024 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FY028384%2F1
• 关键词: Why; do; alpha; cyanobacteria; form

RuBisCO is one of the most abundant enzymes on Earth. Virtually all food webs depend on it to supply fixed carbon. In aerobicenvironments, RuBisCO struggles to distinguish efficiently between CO2 and O2. To compensate, many photosynthetic organismshave developed CO2-concentrating mechanisms (CCMs) to increase the [CO2] around the RuBisCO active site. In cyanobacteria,carboxysomes represent one such CCM, of which two independent forms exist: alpha and beta. This ancient photoautotrophiclineage has succeeded in colonizing habitats worldwide, being primary producers of great ecological importance. Amongst them,cells of the genera Prochlorococcus and Synechococcus, the two most abundant photosynthetic taxa on Earth, dominate oceanicecosystems. These marine picocyanobacteria possess a form IA RuBisCO and alpha-carboxysomes (so-called alpha-cyanobacteria).The remainder of the cyanobacterial radiation was thought to possess beta-carboxysomes and a form IB RuBisCO (beta-cyanobacteria), including freshwater unicellular and filamentous bloom-forming taxa comprising model organisms used inlaboratories worldwide e.g. Synechococcus elongatus and Synechocystis. However, recently I have isolated and sequenced thegenomes of many new unicellular freshwater picocyanobacteria that are phylogenetically much closer to their marine counterpartsand which also possess a form IA RuBisCO and alpha-carboxysomes. Moreover, these organisms have been detected in highabundance in freshwater lakes and reservoirs worldwide. Thus, alpha-cyanobacteria dominate all aquatic systems. CYANORUB seeksto address why this is the case. We hypothesize that alpha-cyanobacteria dominate large, temporally stable water masses,characterized by well-buffered pHs and relatively slow changes in carbonate chemistry. CYANORUB will be crucial for accuratelypredicting the biosphere's response to changing CO2, pH and carbonate chemistry and has biotechnological applications aimed atimproving plant growth.

Rubisco是地球上最丰富的酶之一。几乎所有食物网都依靠它提供固定碳。在多氧环境中，Rubisco努力在二氧化碳和O2之间有效区分。为了补偿，许多光合生物乳果产生了CO2浓缩机制（CCM），以增加Rubisco活性位点周围的[CO2]。在蓝细菌中，羧化体代表一种这样的CCM，其中存在两种独立形式：alpha和beta。这座古老的光自营养基础已成功地在世界范围内殖民栖息地，是生态重要性的主要生产者。其中，甲氯环球菌和Synechococcus属的细胞是地球上两个最丰富的光合分类单元，主导了海洋生物系统。这些海洋上皮细菌具有IA rubisco和α-羧化体（所谓的α-甲状腺细菌）形式。剩余的氰基细菌辐射被认为具有β-羧基助理体和包括beta rubisco（包括beta-cyanobacteria and fill fielwater fillouse nimealwater nimicallult osical nimicallult osical ofersellult fillou fillou fillount fillount of Filloult fillou fillount）全球企业家，例如弹c和synechocystis。但是，最近，我已经分离并测序了许多新的单细胞淡水皮基氨基杆菌的基因组，它们在系统发育上更靠近其海洋对应物，它们也具有IA rubisco和alpha-carboxysomes的形式。此外，这些生物已经在全球淡水湖泊和水库中的高压中被发现。因此，α-甲状腺细菌占主导地位。 Cyanorub Seeksto解决了为什么是这种情况。我们假设α-甲状腺杆菌占据了大型，暂时稳定的水肿块，其特征是缓冲良好，碳酸盐化学的变化相对较慢。 Cyanorub对于准确预测生物圈对变化的CO2，pH和碳酸盐化学的反应至关重要，并且具有旨在旨在atimprove植物生长的生物技术应用。