不同碳源条件下草菇内切型纤维素酶基因（eg1）转录表达的分析

利用Northernblot方法分析了不同碳源条件下草菇切型纤维素酶基因(eg1)的表达.结果发现,在含有纤维素的液体培养基中生长10d,eg1在草菇菌丝中有高效表达;纤维二糖、α-乳糖、β-乳糖,也能诱导eg1的表达,但和纤维素相比,eg1的表达量相对较低,并且它们的诱导效应在加入这类糖12h后迅速减弱;槐糖和龙胆二糖的诱导作用非常弱.在天然稻草为基质的固体栽培料生长时,草菇eg1的表达和草菇菌丝生长与出菇相对应,在菌丝生长期(d8)可见eg1的表达,d12时菌丝已长满,表达减弱,在出菇及菇体的分化及增大期,eg1的表达量逐渐增强,在成熟期达到最高水平;表明在草菇菇体发育中需要更多碳源及能源的补充,eg1在这方面起着非常重要的作用.图4参14     

Land-Use Planning in the Chaco Plain (Burruyacú, Argentina): Part 2: Generating a Consensus Plan to Mitigate Land-Use Conflicts and Minimize Land Degradation

The Burruyacú district (Tucumán province, Northwest Argentina) has been traditionally an area with rural activities based on the exploitation of the Chaco forest for timber and livestock browsing. Since the 1960s, local institutions started promoting soybean due to favorable land conditions and good market prices. Soybean extension, as from the 1970s, has resulted in important reduction of the Chaco forest and also caused physical soil degradation, especially soil compaction and erosion. A land-use-planning exercise was carried out using the Land-Use Planning and Information System (LUPIS) as a spatial decision support system. LUPIS facilitates the generation of alternative land-use plans by adjusting the relative importance attributed by multiple stakeholders to preference and avoidance policies. The system leads to the allocation of competing land uses to land map units in accordance with their preferred resource requirements, conditional upon the resource base of the area and the stakeholders' demands. After generating a land use plan for each stakeholder category identified in the study area, including commercial farmers, conservative/conventional farmers, and conservationists, a consensus plan was established to address the land-use conflicts between mechanized agriculture, traditional agriculture and forest conservation, and to mitigate soil degradation caused by extensive dry-farming. Although the planning exercise did not directly involve the stakeholders, the results are sufficiently practical and realistic to suggest that the approach could be extended to the entire Chaco plain region.     

Are bioplastics an ecofriendly alternative to fossil fuel plastics?

Environmental Chemistry Letters - More than 390 million tons of fossil fuel plastics have been produced in 2022, and plastic pollution has become a major health issue for humans and ecosytems....     

Land-Use Planning in the Chaco Plain (Burruyacú, Argentina). Part 1: Evaluating Land-Use Options to Support Crop Diversification in an Agricultural Frontier Area Using Physical Land Evaluation

The Burruyacú district (Tucumán province, Argentina) is a farming frontier in the western Chaco plain, at the foothills of the sub-Andean mountain ranges, where agricultural land-uses are in conflict with the conservation and management of the Chaco forest. Over the last decades, large-scale farming rapidly expanded due to population pressure, attractive market prices, easy accessibility, favourable annual rainfall, fertile soils, and flexible land tenure. Cropland extension, mainly for heavily mechanized soybean production, has resulted in important reduction of the Chaco forest and also caused physical soil degradation, especially soil compaction, and soil erosion. Land suitability was assessed using the Food and Agriculture Organization (FAO) framework for a set of crops ecologically adapted to the area, including soybean, maize, wheat, sugarcane, citrus, and safflower. Only 16% of the study area has high suitability for most of the selected crops. Major limitations for cropping are low annual rainfall and flooding in the east of the study area, and topography (slope) and flooding in the west. As climate varies over relatively short periods of time, with recurrent cycles of dry and rainy years, land suitability for the selected crops was also assessed under extreme but realistic climatic conditions. Under rainy-year conditions, almost all the study area is unsuitable or marginally suitable for most of the crops. Under dry-year conditions, the study area is unsuitable for all crops, except safflower, which is more drought-resistant. This article proposes alternatives to the mono-cropping of soybean with the aim to help farmers make adequate decisions on land-use and management under deteriorating environmental conditions and for addressing the issue of competitive land uses in the context of land-use planning.     

不同碳源条件下草菇内切型纤维素酶基因(egl)转录表达的分析

利用Northern blot方法分析了不同碳源条件下草菇內切型纤维素酶基因(eg1)的表达.结果发现,在含有纤维素的液体培养基中生长10 d,eg1在草菇菌丝中有高效表达;纤维二糖、α-乳糖、β-乳糖,也能诱导eg1的表达,但和纤维素相比,eg1的表达量相对较低,并且它们的诱导效应在加入这类糖12 h后迅速减弱;槐糖和龙胆二糖的诱导作用非常弱.在天然稻草为基质的固体栽培料生长时,草菇eg1的表达和草菇菌丝生长与出菇相对应,在菌丝生长期(d 8)可见eg1的表达,d 12时菌丝已长满,表达减弱,在出菇及菇体的分化及增大期,eg1的表达量逐渐增强,在成熟期达到最高水平;表明在草菇菇体发育中需要更多碳源及能源的补充,eg1在这方面起着非常重要的作用. 图4 参14     

Polylactic acid synthesis,biodegradability, conversion to microplastics and toxicity: a review

Global pollution by plastics derived from petroleum has fostered the development of carbon–neutral, biodegradable bioplastics synthesized from renewable resources such as modern biomass, yet knowledge on the impact of bioplastics on ecosystems is limited. Here we review the polylactic acid plastic with focus on synthesis, biodegradability tuning, environmental conversion to microplastics, and impact on microbes, algae, phytoplankton, zooplankton, annelids, mollusk and fish. Polylactic acid is a low weight semi-crystalline bioplastic used in agriculture, medicine, packaging and textile. Polylactic acid is one of the most widely used biopolymers, accounting for 33% of all bioplastics produced in 2021. Although biodegradable in vivo, polylactic acid is not completely degradable under natural environmental conditions, notably under aquatic conditions. Polylactic acid disintegrates into microplastics faster than petroleum-based plastics and may pose severe threats to the exposed biota.