土壤日晒在绿色植保中的应用与展望

土壤消毒主要用于土壤病虫草害防控。过去几十年,土壤主要采用化学药品熏蒸消毒,不合理使用容易造成环境污染。土壤蒸汽消毒、火焰消毒和热水浇灌等需要专门的仪器设备,且存在能耗较高、灭生性强、容易破坏土壤结构等缺点。目前,土壤日晒技术受到意大利、美国、以色列等70多个国家农业科学家的广泛关注,但在中国依然处于初级阶段。本文总结了国内外学者关于土壤日晒对农业病虫草害、土壤肥力、农作物产量等方面的影响与应用,分析了土壤日晒存在的局限性,并对土壤日晒在未来农业绿色防控上的应用前景进行了展望,以期为农产品无公害生产提供理论依据和实践参考。     

Can water disinfection prevent the transmission of infectious koi herpesvirus to naïve carp? – a case report

Hygienic measures such as disinfection are important tools for the maintenance of fish health in aquaculture. While little information is available on the disinfection of water intended for fish containment, Huwa‐San^®, a disinfectant used in food and water industries, was used for daily treatment at concentrations of approximately 60 ppm over a total period of 3 months (experiment 1) with a 3‐week treatment‐free interval after 2 months (experiment 2). During this period, koi herpesvirus (KHV) was added to the water of two aquaria, one used as a normal contact control, the other one receiving daily water disinfectant treatments that prevented KHV infection of carp. In the second experiment, Huwa‐San^® treatment was interrupted and KHV infection was prevalent. However, when naïve fish were introduced to the same aquarium after re‐application of disinfectant, KHV could not be detected in those naïve fish. Whilst KHV could not be detected in samples where disinfectant had been applied, it was present in samples of naïve fish cohabiting with infection contact control animals which had undergone no disinfectant treatment over experiments 1 and 2. The results presented here show that water treatment with a disinfectant may prevent transmission of infectious KHV to naïve carp cohabited with infected carp.     

有机基质臭氧消毒设备设计与试验

为实现有机基质的绿色、高效消毒,设计了有机基质臭氧消毒设备。基于离散元软件EDEM建立了有机基质颗粒模型,根据有机质物料输送及抛撒动力学特性与臭氧消毒工艺流程,利用Solid Works软件构建了有机基质臭氧消毒设备结构模型,并对两种模型进行接触参数标定。以有机基质倾尽角为评价指标,以抄板弯折角、转筒转速、填充率为试验因素,进行了三因素五水平正交旋转组合仿真试验。根据仿真结果,利用Design-Expert软件回归分析法建立倾尽角回归数学模型,对有机基质臭氧消毒设备模型中的抄板弯折角、转筒转速、填充率进行了参数优化与试验验证。结果表明,在各因素取值范围内,抄板弯折角对有机基质倾尽角影响极显著,转筒转速对倾尽角影响显著,填充率对倾尽角影响不显著;有机基质臭氧消毒装置最优作业参数组合为:抄板弯折角124.23°、转筒转速6.29 r/min,此时物料倾尽角仿真值为89.3°。臭氧消毒灭菌性能试验验证结果为:臭氧初始质量浓度64.2 mg/m~3,消毒60 min后,细菌灭菌率88.9%,真菌灭菌率97.9%,能够满足有机基质消毒生产要求。     

Salmonella Infantis and Salmonella Enteritidis specific bacteriophages isolated form poultry faeces as a complementary tool for cleaning and disinfection against Salmonella

Salmonellosis represents an important public health concern. Several authors point out the inefficiency of the cleaning and disinfection protocols to remove the bacteria from the field. For this reason, innovative techniques, as bacteriophages, could be implemented to control the bacteria. The main objectives of this study were to assess the effect of bacteriophages against Salmonella Infantis and Salmonella Enteritidis on farm surfaces, and to evaluate bacteriophage procedure application as sanitiser against Salmonella in field conditions. Thus, most prevalent serovars in poultry production were selected (Salmonella Infantis and Salmonella Enteritidis) to contaminate farm facilities. Then, two specific bacteriophages isolated from poultry faeces were applied against them. Results showed Salmonella Infantis and Salmonella Enteritidis decreased of 4.55 log₁₀CFU/mL and 3.85 log₁₀CFU/mL, respectively; the maximum reduction in Salmonella was the 5^th day, after 10⁸ PFU/mL and 10³ PFU/mL bacteriophage application. These results highlight bacteriophages as a promising tool together with cleaning and disinfection.     

过氧化氢和甲醛对SPF级大鼠和小鼠繁殖室消毒效果观察

目的比较观察过氧化氢和甲醛对SPF级大鼠和小鼠繁殖室内表面、台面以及空气的消毒效果,选择消毒效果良好的消毒剂。方法采用空气落下菌检测法和表面细菌拭子检测法,对过氧化氢和甲醛熏蒸SPF级大鼠和小鼠繁殖室的消毒效果进行检测观察。结果SPF级大鼠和小鼠繁殖室分别经过氧化氢和甲醛熏蒸消毒后,进行空气落下菌的检测,过氧化氢和甲醛对大鼠繁殖室和小鼠繁殖室空气的杀菌率分别为100%、97.5%和100%、100%;将墙壁、地面和笼架表面的菌落数进行检测,过氧化氢和甲醛对大鼠繁殖室墙壁、地面和笼架的杀菌率分别为100%、99%、100%和95%、100%、99%,对小鼠繁殖室墙壁、地面和笼架的杀菌率均为100%。结论过氧化氢蒸汽消毒是比较理想的消毒方法,很好地控制了SPF级大鼠和小鼠繁殖室环境微生物,安全性高且消毒效果明显。     

Disinfection of almaco jack (Seriola rivoliana Valenciennes) eggs: Evaluation of three chemicals

Almaco jack (Seriola rivoliana Valenciennes) is an excellent candidate for aquaculture due to its fast growth rate and high market value. While S. rivoliana have adapted well to captivity, survival at early life stages can be improved to increase profitability during production. A wide range of variables cause larval mortalities but high bacterial loads in rearing tanks are often correlated with these losses. The aim of this study was to investigate the effect of egg disinfection on bacterial load and hatch rate of S. rivoliana. Disinfectants tested included formalin (F100 and F200; 100 and 200 mg/L, respectively, for 60 min), hydrogen peroxide (HPO; 300 mg/L for 10 min) and peracetic acid/hydrogen peroxide (PAA/HPO; 15.7 mg/L/39.6 mg/L for 1 min). Concentrations and contact times were determined based on current use in marine aquaculture and preliminary trials. Eggs treated with HPO and F100 had significantly higher hatch rates than the untreated control group. All treatments significantly decreased total Vibrio counts compared to untreated eggs; however, total bacterial counts were only decreased following treatments with PAA/HPO and F200. To prevent egg mortality due to bacterial overgrowth, consideration should be given to the use of surface disinfection using HPO or F100. Future studies should investigate the use of peracetic‐based products at lower doses.     

Effect of disinfection with peracetic acid on the microbial community of a seawater aquaculture recirculation system for Pacific white shrimp (Litopenaeus vannamei)

When tropical shrimps are kept in recirculating aquaculture systems (RAS), one of the limiting factors is the maintenance of a sufficient water quality, and therefore, often disinfectants like peracetic acid (PAA) are added to the water either as prophylactic or treatment measure. In this study, PAA in concentrations of 0.1 mg/L, 1 mg/L and 10 mg/L was applied continuously for 56 days to small-scale seawater RAS stocked with Litopenaeus vannamei. Treatment with 0.1 mg/L did not result in a reduction in the total bacterial amount and therefore was not effective. A concentration of 10 mg/L led to significant changes in the chemical water parameters already after 2 days and was therefore not recommendable. A concentration of 1 mg/L led to increased levels of ammonia and nitrite within 2 days and to a significant increase in the bacterial amount in the water, most probably due to an enhanced growth of heterotrophic bacteria. The microflora showed significant fluctuations, and there were indications that the welfare of the shrimps was affected. Using 1 mg PAA/L for prophylactic use is therefore also not recommendable but might be an alternative option for short-term treatment in cases of disease outbreaks.     

Use of a foaming disinfectant and cleaner to reduce aerobic bacteria on poultry transport coops

Poultry transportation coops are rarely washed and have been demonstrated to be a point of cross-contamination of broiler carcasses. Foaming disinfectants and cleaners, commonly used within processing plants, may be used to clean and disinfect poultry transportation coops. In this study, homogenized fecal material was evenly applied to the floors of precleaned broiler transportation coops and allowed to dry. Treatments consisted of a water rinse, a foam additive alone, foaming cleaner, and a disinfectant plus a foam additive. All foaming treatments were applied using a compressed air foam system (2,271 L/min; 600 gal/min), similar to what firefighters would use. A high-pressure water rinse (HPWR) was added prior to or following the treatments to determine whether rinsing prior to product application or rinsing after product application would improve efficacy. Based on our data, a compressed air foam system may be used in combination with a commercially available disinfectant or foam cleaner to reduce aerobic bacteria on the surfaces of commercial broiler transportation coops. Furthermore, the addition of a HPWR did not further reduce the level of aerobic bacteria on broiler transportation coop floors.     

二氧化氯应用于水厂消毒的优缺点

本文作者根据二氧化氯自身特点及在水厂中的实践,论述了二氧化氯的主要物理性能,消毒氧化作用,制取方法,以及在水厂消毒中的应用。     

微波处理松材线虫病疫木技术研究

该文对利用微波处理松材线虫病疫木技术进行了研究，结果表明：不论木材厚薄大小、含水量多少、在微波处理炉腔内怎样堆放，以及环境温度、微波功率等因素的如何变化，只要SWB-Ⅱ型隧道式微波除害处理设备显示的木材表面温度大于68℃，持续30min，就能有效地杀死松木中的松褐天牛和松材线虫。