Iron (oxyhydr)oxides (FeO) significantly influence the environmental dissemination of antibiotic resistance genes (ARGs) by adsorbing ARG-carrying DNA through phosphate interactions. However, the fate of FeO-adsorbed DNA, particularly its release dynamics and impact on ARG dissemination in the presence of inorganic phosphate with environmentally relevant concentrations (Pie), remains unclear. Using goethite (a representative FeO mineral) and diverse DNA forms (three linear fragments, one ARG-carrying plasmid), this study quantified Pie-driven DNA desorption via a novel successive desorption-extraction protocol, distinguishing readily desorbable DNA from residual DNA. Pie (1.0-10 mg P L-1) displaced 5-96% of adsorbed DNA. Structurally, the shorter linear DNA and supercoiled plasmid formed fewer Fe-O-P bonds per adsorbed molecule, enhancing Pie-driven displacement and subsequently increasing their desorbable fraction, yielding a two-stage response to Pie fluctuations (minimal below 0.2-0.5 mg P L-1; substantial above). Critically, Escherichia coli transformation assays showed that while goethite adsorption suppressed ARG transfer, Pie-activated desorption restored transformation efficiency. These results resolve the unverified link between realistic Pie fluctuations (e.g., paddy field fertilization/sediment hydrology) and FeO-bound DNA release, demonstrating its potential role in ARG dissemination. This mechanistic insight is essential for risk assessment of ARG transmission in iron-rich ecosystems and strategic deployment of FeO materials for soil ARG mitigation.

A built-in electric field strategy was applied to construct a heterogeneous N-doped spirulina biochar-supported nZVI composite (NBC-nZVI) for efficient sulfite (S(IV)) activation in water purification. The NBC-nZVI/S(IV) system was systematically evaluated through degradation kinetics, reactive oxygen species (ROS) analysis, toxicity evaluation and mechanistic investigations with theoretical and experimental studies. Remarkably, the system achieved 98.4 % norfloxacin (NOR) removal within 120 min, with an apparent rate constant (kobs) of 0.1491 min-1 , surpassing NBC-nZVI and NBC/S(IV) systems by 2.1-fold and 11.0-fold, respectively. Mechanistic studies revealed that NBC-nZVI modulated the d-band center and facilitated interfacial charge redistribution, enhancing S(IV) adsorption, charge separation and transfer and the iron cycle, which significantly boosted ROS generation, with center dot O2- identified as the dominant ROS. This work demonstrates a highly efficient S(IV)-based advanced oxidation process, offering a sustainable and scalable solution for removing fluorinated contaminants in water treatment, with significant implications for environmental remediation and catalyst design.

The urgent need for sustainable water purification technologies to remove halogenated pollutants, particularly antibiotics, continues to drive innovation in environmental remediation. In this study, we propose a simple and scalable strategy to develop an activated carbon supported sulfidized nanoscale zero-valent iron (S-nZVI-AC) for efficient florfenicol (FF) removal under ambient conditions. Leveraging the synergistic interplay of sulfidation and carbon support, S-nZVI-AC outperformed conventional nZVI systems, delivering a high-rate constant (k1 = 0.39 min-1) and surface-area-normalized activity (kSA = 9.94 mL m-2 min-1). Experimental results and DFT calculations demonstrated that the rectifying contacts between S-nZVI and AC generated built-in electric fields, reprogramming the interfacial electronic structure and accelerating electron transfer. This facilitated halogen bond cleavage and reactive site exposure, effectively overcoming the kinetic bottleneck in FF degradation. S-nZVI-AC exhibited strong environmental compatibility, achieving >90 % FF removal in natural waters and 70 % in pharmaceutical wastewater, while substantially reducing post-reaction toxicity and posing negligible material-associated hazards. This work offers a viable route to tailor interfacial electronic structures via synergistic sulfidation-carbon coupling and offers new insights into the rational design of high-efficiency, low-consumption remediation materials for sustainable water purification.

The prevalent emerging contaminant 6PPD-quinone (6PPDQ) in aquatic environments has attracted great attention due to its acute mortality in coho salmon when exposed to urban runoff. It cannot be ignored that 6PPDQ exists as a pair of enantiomers (R-6PPDQ and S-6PPDQ), which may undergo enantioselective transformation in aquatic organisms and cause more complex ecological risks. However, a clear chiral molecular mechanism is lacking for the 6PPDQ, hindering the accurate assessment of the risks of 6PPDQ to aquatic organisms. Herein, this study investigated the precision stereoselective transformation of rac-/R-/S-6PPDQ through experiments and computations. Mass spectrometry results identified different types of hydroxylation metabolites, where significant non-racemization (EF = 0.6) enantiomer-selective transformation was observed. Subsequently, density functional theory (DFT) calculations were performed to explore the potential biotransformation pathways of phenyl oxidation (e.g., ortho- and para- positions) and alkyl oxidation (e.g., C30 and C40 positions). Importantly, there was a nearly 7 kcal/mol relative barrier difference between the rate-determining steps of alkyl-C40 hydroxyl R-6PPDQ and S-6PPDQ, calculated by the accurate quantum mechanical/molecular mechanical (QM/MM) method to consider the active center model and the enzyme environment simultaneously. The overall metabolism presented an interesting conclusion that R-6PPDQ was more easily catalyzed and metabolized than S-6PPDQ. These findings first elucidate the stereoselective bio-metabolism of chiral 6PPDQ by using a synergy strategy, which is helpful for us to develop metabolites as biomarkers for tracking, monitoring, predicting and effectively controlling contaminants in aquatic ecosystems, laying the foundation for accurately assessing the ecological risks of emerging contaminants.

The impact of iron (hydr)oxide adsorption on nucleotides and nucleic acids (NNAs) in the environment varies.

While p-phenylenediamine antioxidants (PPDs) pose potential risks to aquatic ecosystems, their environmental persistence and transformation remain ambiguous due to the undefined nature of PPD C-N bond hydrolysis. Here, we investigated the hydrolysis patterns of PPDs by analyzing their hydrolysis half-lives, hydrolysis products around neutral pH (pH 6.0-7.7), and the role of atoms within the C-N bonds in PPDs. Hydrolysis preferentially targets the aromatic secondary amine N with the strongest proton affinity and the C atom of C-N with the highest nucleophilic-attack reactivity. The hydrolysis half-life (t1/2) shortens when the maximum proton affinity of N increases. These results are supported by theoretical calculations, demonstrating a hydrolysis reaction propelled by proton transfer from water to N and complemented by aromatic nucleophilic substitution of N in C-N by water hydroxyl. With the experimental results and the atom reactivity-based predictive model, the t1/2 around neutral pH for 60 PPDs (monitored in environment, commercially available, or under investigation) is determined, showing variations ranging from 2.2 h to 47 days. The model prediction of primary C-N hydrolysis is confirmed through typical PPDs. With the elucidated mechanism and developed model, this research provides new insights into PPD hydrolysis, underscoring its significance in delineating environmental impacts.

Antibiotics, especially halogenated antibiotics, inevitably discharged into environment are of great concern worldwide. Nanoscale zerovalent iron (nZVI)-based materials have been promising for the removal of halogenated antibiotics, but their susceptibility to oxidation and aggregation badly limits their application. Herein, activated carbon (AC)-supported nZVI (nZVI-AC) was synthesized to remove florfenicol (FF), a widely used broad-spectrum halogenated antibiotic, under ambient conditions. nZVI-AC had the strongest adsorption affinity to FF and most conductive to FF, and the reaction rate constant (k1) of FF removal by nZVI-AC (0.320 min -1) was increased by 106.7 times with the support of AC (0.003 min-1). Freundlich and DA models showed good fits for FF adsorption by nZVI-AC, and hydrogen bonding, van der Waals forces and chemisorption were the dominant mechanisms for FF adsorption. The van der Waals forces and chemisorption contributed to the enhanced adsorption capacity of the composite system, and the strong synergistic effect of AC and nZVI in nZVI-AC accelerated electron transfer towards adsorbed FF, thus facilitating the further dehalogenation. The removal of FF by nZVI-AC was dependent on solution pH and CrO42-concentrations, and suppressed by humic acid, while barely affected by Cd2+. Escherichia coli survival assessment and theoretical simulation evaluation demonstrated the superior efficacy of nZVI-AC in detoxifying FF with the detection of non-toxic FF intermediates. By comprehensively analyzing the environmental factors, removal mechanisms and potential degradation pathways of FF treated by nZVI-AC, this study provides further insights into the risk assessment of intermediates and their toxicity, assigning new perspectives for practical application of nZVI-based technologies to efficiently remove the amount and also reduce the toxicity of FF and other emerging contaminants in water.

Biochar has great potential in reducing the abundance of antibiotic resistance genes (ARGs) and mobile genetic elements (MGEs) from soil. However, its efficiency in removing other biological pollutants, such as human bacterial pathogens (HBPs) and virulence factor genes (VFGs), is rarely studied. Herein, by pyrolyzing rice straw (RS) and pine wood (PW) at 350 and 700 °C, we prepared a series of biochar (RS350, RS700, PW350, and PW700) and investigated their impacts on the abundance and pathogenicity of HBPs. Compared with PW biochar, RS biochar effectively reduced the abundance of HBPs by 6.3-40.1%, as well as their pathogenicity, evidenced by an 8.2-10.1% reduction in the abundance of VFGs. Mechanistically, more persistent free radicals (PFRs) were formed in RS biochar than that of PW biochar during pyrolysis, and PFRs triggered the degradation of N-butyryl-l-homoserine lactone (C4-HSL) from 1.05 to 0.68 ng/kg, thereby disturbing the quorum sensing (QS) of HBPs. Once the QS was disturbed, the communications among HBPs were hindered, and their virulence factors were reduced, which ultimately lowered the abundance and pathogenicity of HBPs. Collectively, our study provides insights into the role of biochar in decreasing the risks of HBPs, which is significant in the development of biochar-based technologies for soil remediation.

The char component of biochar can act as an electron shuttle and redox agent to accelerate the transformation of ferrihydrite, but how the silicon component of biochar affects ferrihydrite transformation and pollutant removal remains unclear. In this paper, infrared spectroscopy, electron microscopy, transformation experiments and batch sorption experiments were conducted to examine a 2-line ferrihydrite formed by alkaline precipitation of Fe3+ on a rice strawderived biochar. Fe-O-Si bonds were developed between the precipitated ferrihydrite particles and biochar silicon component, increasing mesopore volume (for mesopores with diameters of 10-100 nm) and surface area of ferrihydrite as the Fe-O-Si formation probably alleviated the aggregation of ferrihydrite particles. The Fe-O-Si bondingcontributed interactions blocked the transformation to goethite for ferrihydrite precipitated on biochar in a 30-day ageing and a 5-day Fe2+ catalysis ageing. Moreover, there was an increase of oxytetracycline adsorption capacity onto ferrihydrite-loaded biochar, which reached amazingly 3460 mg/g at the maximum, due to the Fe-O-Si bonding-contributed increase of surface area and oxytetracycline coordination sites. Ferrihydrite-loaded biochar as a soil amendment enhanced oxytetracycline adsorption and reduced the bacterial toxicity of dissolved oxytetracycline better than ferrihydrite did. These results provide new perspectives for the role of biochar (especially its silicon component) as an iron-based material carrier and a soil additive in the environmental effects of iron (hydr) oxides in water and soil.

羊肚菌是世界上久负盛名的高档食用菌.我国自2010年开始进行羊肚菌人工栽培至今,年栽培面积已增加近300倍,成为发展最快的食用菌菇种.然而,由于羊肚菌人工驯化栽培还处于起步阶段,对其遗传特性、菌种种性保持和栽培模式等关键技术还缺乏深入、系统的研究,同时,对不同气候、地理和环境等对栽培的影响也缺乏足够的认识,加上羊肚菌栽培受土壤、微生物区系和病虫害等其他综合因素制约,羊肚菌栽培仍然具有很大的不确定性.

诺氟沙星(Norfloxacin,NOR)是一种含有C-F键的难降解抗生素,具有强持久性和较高毒性,传统的处理方法难以有效去除NOR.基于过硫酸盐的高级氧化技术具有较高的选择性、适应性、去除效率等优点,已被广泛研究用于有机污染物的去除.本研究以螺旋藻为原材料热解得到的生物炭(Biochar,BC)为基底,选取具有高还原能力的纳米零价铁(Nanozero-valent iron,nZVI)作为其可能的活性中心,将nZVI负载至BC表面制备了生物炭负载纳米零价铁(nZVI-BC),以综合发挥碳载体与铁活性中心的作用高效催化过硫酸盐降解有机污染,并通过研究nZVI-BC的结构特征和对NOR的去除效率,探究其对过一硫酸盐(Peroxymonosulfate,PMS)的活化效能及机理.结果表明,nZVI-BC活化PMS降解NOR具有优异的催化性能,其降解效率随着材料碳铁负载质量比(C/Fe)的减少而升高,在最佳反应条件下,当C/Fe=1∶1时,120 min内nZVI-BC/PMS对NOR的去除率可达到98.8％.降解过程符合拟一级动力学,nZVI-BC/PMS体系在2 min内的降解速率可达(0.69±0.09)min-1,分别是nZVI和BC800催化PMS体系的2.55倍和6.27倍,且弱酸条件(pH=4.00)及温度升高(T=45℃)更利于nZVI-BC催化PMS降解NOR.nZVI-BC/PMS降解NOR是以·OH、·SO4和参与的自由基途径及以1O2主导作用的非自由基途径的协同效果,贡献作用为1O2＞·SO4＞·OH＞·O2,其中,1O2在整个反应路径中起至关重要的作用,贡献率达38.46％.据降解产物分析,得知NOR在nZVI-BC/PMS体系中的降解主要是通过脱氟和哌嗪环的开环裂解,最终转化为短链酸、CO2和H2O.本研究为实现NOR在水体中的高效去除提供了一种实际可用、高效环保的方法,同时为阻控新型污染物和抗生素耐药污染提供了新策略.

Decreasing bioaccessible antibiotics, heavy metals, and antibiotic resistance genes (ARGs) in soil by adsorption is an attractive, but unrealized, approach for ARG risk reduction. This approach has the potential to reduce the (co)selection pressure from antibiotics and heavy metals on bacteria and ARG horizontal gene transformation to pathogens. Here, a wet-state silicon-rich biochar/ferrihydrite composite (SiC-Fe(W)) synthesized by loading ferrihydrite onto rice straw-derived biochar was examined for i) adsorption of oxytetracycline and Cu2+ to reduce (co)selection pressure and ii) adsorption of extracellular antibiotic resistance plasmid pBR322 (containing tetA and blaTEM-1) to inhibit ARG transformation. SiC-Fe(W) gained the adsorption priority of biochar (for Cu2+) and wet-state ferrihydrite (for oxytetracycline and pBR322) and showed adsorptive enhancement (for Cu2+ and oxytetracycline) from a more wrinkled and exposed surface from biochar silica-dispersed ferrihydrite and a more negatively charged biochar, and the adsorption capacity for SiC-Fe(W) was 17-135 times that of soil. Correspondingly, 10 g/kg SiC-Fe(W) amendment increased the soil adsorption coefficient Kd by 31%-1417% and reduced the selection pressure from dissolved oxytetracycline, co-selection pressure from dissolved Cu2+, and transformation frequency of pBR322 (assessed with Escherichia coli). The development of Fe-O-Si bonds on silicon-rich biochar in alkaline enhanced ferrihydrite stability and adsorption capacity (for oxytetracycline), presenting a new potential strategy of biochar/ferrihydrite composite synthesis for adsorptive inhibition of ARG proliferation and transformation in ARG pollution control.

溶解性生物炭受紫外光辐射产生的活性氧自由基(Reactive oxygenspecies,ROS)易对环境造成影响,受到环境领域的持续关注.以玉米秸秆为原料,在不同裂解温度(200～600℃)下制备了 5种生物炭,并通过水提得到溶解性生物炭(Dissolved biochar,DBC),系统考察了生物炭裂解温度对DBC结构和组分的影响,并利用化学分子探针定量研究了 DBC在紫外光辐射下产生常见ROS的能力,如羟基自由基(Hydroxyl radical,·OH)、单线态氧(Singlet oxygen,1O2)和超氧自由基(Superoxide radical,O2·-).结果表明,DBC主要由有机酸、类蛋白质和纳米级生物炭构成,前两者皆会随生物炭裂解温度上升而减少,后者则会逐渐增多.高温DBC-(400～600℃)具有更强芳香性和疏水性,但荧光物质含量极低.对DBC产生的ROS进行定量研究发现,仅DBC-200℃和300℃产生少量·OH.DBC-300℃的1O2表观量子产率(Φ1O2)最多,为7.41％;DBC-400℃的O2·-表观量子产率(ΦO2·-)最多,为2.12％.DBC-300℃中荧光物质和腐殖酸类物质更多,羰基和醛醌类官能团比例最高,促进其产生更高的102含量;DBC-400℃芳香性结构丰富且更强,促进其产生更高的02·-含量.DBC经长期紫外光辐照(168h)后,芳香性降低,高分子量化合物减少,自身也会通过光矿化形式(约30％)参与碳循环.本文为阐明DBC自身光降解、光敏化ROS产能和组成结构间的构-效关系提供了理论依据,为DBC潜在的环境污染修复应用奠定了坚实基础.

为了筛选出适合工厂化栽培的杏鲍菇优新品种,我们从浙江大学农业与生物技术学院食用菌研究中心引进杏鲍菇新品种天鸣1号(浙认菌2018001),并进行工厂化周年栽培试验,结果显示,天鸣1号菌丝体生长旺盛,洁白、 平展、 气生菌丝中等,生长速度为4 mm·d-1,无色素,无星网状菌落现象;子实体丛生,中偏小,菌盖直径3.0～4.9 cm,浅栗色,菌柄呈棍棒型;孢子印白色,孢子呈椭圆形或近纺锤形,大小3.15μm×6.69μm.在袋式栽培时,菌丝满袋时间44 d,后熟时间10 d,菌袋成品率99.5％.栽培全生育期63 d,每袋产量329.2 g,总生物转化率73.2％.可采用免疏蕾栽培方法,效率高,病害少,品质佳,尤其是多糖含量达到83.2 g·kg-1,是理想的进口替代品种.

Ligand exchange (LE), comprising Fe-O-P formation and OH- release, regulates phosphate-iron (oxyhydr)oxide interactions and their environmental effects in water and soil. Although their multiple P-OH groups render many organic phosphates more favorable than orthophosphate for LE on iron (oxyhydr)oxides, the question remains of how many organic P-O(H) groups (including P-OH and P-O-) contribute to LE and phosphorus adsorption. Here, we confirmed that the LE sites on goethite at pH7.0 for monomeric, oligomeric and nucleic acid organophosphate are also those for orthophosphate, and the stoichiometric relationship between P-O(H) engaged in LE and OH- exchanged from goethite (SP-OH~OH-) is the same for both types of phosphate. Accordingly, organic P-O(H) groups involved in LE can be discriminated by the SP-OH~OH- probed by orthophosphate. For nucleotide monophosphates, diphosphates, triphosphates, and nucleic acids, the number of P-O(H) groups engaged in LE per adsorbed molecule increased from 2 to 2110-29600 because of increased molecular P-O(H) groups, while LE versus adsorbed P-O(H) decreased from 100% to 24.7-40.2% due primarily to nucleic acid clustering-caused shielding of P-O(H). The quantified amount of P-O(H) involved in LE per adsorbed molecule and relative to adsorbed mass elucidated the variations in phosphorus adsorption, as these parameters reflect the LE-motivated adsorption force and molecular mass burden of LE in adsorption, respectively. This LE-based stoichiometry will promote the understanding of environmental organophosphorus-iron coupling.

Landfills are sites for the disposal of waste over decades. The dynamics of contaminants during landfill treatment influence the functions and environmental risks of the landfill systems, but the patterns of these dynamics are not fully characterized, especially for antibiotic resistant genes (ARGs), an emerging contaminant of global concern. Here, seventeen typical ARG subtypes were quantitatively investigated in refuse samples from small and medium-sized landfills with ages of <3 years, ~5 years, and 8–10 years. The abundance of ARGs, including tetM, tetX, blaPER, emrB, sul1 and sul2, increased significantly (p < 0.05), approaching 8- to 304-fold on average, from refuse of < 3years to that of 8–10 years, while there was no obvious change (p > 0.05) in abundance for other ARGs, including tetQ, tetW, ampC, blaCTX-M, blaSHV, emrA, mefA, qnrD, qnrS, and mexF. Accordingly, resistance to tetracyclines, macrolides, and sulfonamides increased with landfill age, while resistance to β-lactams and quinolones remained unchanged. The increase in ARG abundance with increasing refuse age was probably related with the increased horizontal gene transfer (HGT) (indicated by the increased abundance of mobile gene elements) and the enhanced co-selective pressure (suggested by the increased contents of heavy metals). These results indicated a potential risk from ARG enrichment with an increase in refuse age in small and medium-sized landfills, which should be managed to ensure landfill safety.

以镉污染土种植水稻秸秆为原料,通过500℃不同时间(10～720 min)处理制备秸秆热解产物(生物炭和秸秆灰),测定产物中镉的含量及其溶出性.结果表明,水稻秸秆经热解处理后挥发镉总量的29.6％～48.4％;样品产率随热解时间的增加而下降;单位质量生物炭和秸秆灰中镉含量为2.35～7.05 mg·kg-1和15.0～16.4 mg·kg-1,分别是水稻秸秆中镉含量(0.948 mg·kg-1)的2.5～7.4倍和15.8～17.3倍;通过不同提取剂得到镉溶出率由低到高依次为0％～43.2％(采用0.01 mol·L-1 CaCl2提取)、0％～44.3％(采用Toxicity Characteristic Leaching Procedure提取)、28.8％～58.8％(采用1 mol·L-1 pH 5.0乙酸-乙酸钠单次提取)、35.1％～98.4％(采用1 mol·L-1 pH 5.0乙酸-乙酸钠连续4次提取);随着热处理时间的延长,样品中镉溶出率逐渐降低;由于热解过程中镉的挥发和形态转变,水稻秸秆转变为生物炭和秸秆灰后镉的可溶出总量(采用1 mol·L-1 pH 5.0乙酸-乙酸钠连续4次提取)由0.933 mg·kg-1降至0.223～0.384 mg·kg-1,表明受镉污染的水稻秸秆热解转化为生物炭和秸秆灰可以有效缓解镉潜在的溶出风险.

Pyrogenic char (biochar) with a high sorption capacity (B-HSC) can sequester hazardous chemicals (e.g., phenanthrene). However, when sorption inhibits bioavailability of some functional chemicals (e.g., the herbicidal efficacy of diuron in soil), biochar with a low sorption capacity (B-LSC) is required to prevent sorption effects. The pyrolytic B-HSC generation has been reported, but information on B-LSC formation is scarce. How fast B-HSC and B-LSC could be generated is unknown until now. Here, biochars were rapidly prepared (the shortest heating time reached 5 min and the cooling time reached < 30 min) by a direct-pyrolysis method by directly exposing packaged rice straw and pine wood to 350 degrees C, 500 degrees C and 700 degrees C and out-of-furnace cooling at room temperature. The sorption of diuron, phenanthrene, and twelve other chemicals was investigated. B-HSCs were obtained within 30 min of rice straw pyrolysis, and the biochar K-d values quickly increased to 7-730-fold that of the raw biomass as -OH and C-O-C in (hemi)cellulose of rice straw rapidly degraded, increasing hydrophobic interactions between the char and chemicals (solubility <= 82.8 g/L). In contrast, B-LSCs were generated within 30 min of PW pyrolysis, and the K-d values of the biochars were 0.2-3.0-fold that of the raw biomass, as the surface area development and hydrophobicity-driven sorption were probably delayed by the late degradation of lignin aromatic C-O and phenolic -OH. Biochar amendment revealed an enhancement effect of B-HSC but not of B-LSC on soil sorption. The fast formation of B-LSC and B-HSC provides a guide to develop time- and cost-effective technique in pyrolytically producing weakly or strongly sorbing biochars for organic chemical management. (C) 2021 Elsevier Ltd. All rights reserved.

Oyster mushroom ( Pleurotus geesteranus Singer) is grown widely in China withut problems, but occasionally severe bacterial contamination occurred in cultivation bags of Pleurotus geesteranus during high summer temperatures in some companies in the Chunan county of Zhejiang province in 2018, belonging to the so-called Bacillus pumilus group by morphological characteristics, 16S rRNA, GyrB and aroE genes sequencing, fatty acid analysis and MALDI analysis. The inoculation tests confirmed that Bacillus pumilus strains were contaminants causing mycelial disappearance of P. geesteranus . The dual culture tests demonstrated that several strains of B. pumilus were able to inhibit mycelial growth of P. geesteranus . In order to find the sources of contamination the, process of mushroom cultivation was investigated. A 41.0% contamination rate occurred in cultivation bags with sponge plugs, as opposed to a very low contamination rate (<4%) in cultivation bags with cotton plugs. It was also shown that a 13.0% bacterial isolation rate was obtained from autoclaved sponge pieces, as opposed to 2.0% or 0.0% from cotton pieces, respectively. Fifteen strains isolated all were identified by MALDI-Biotyper as Bacillus spp., belonging to four species ( Bacillus circulans , B. pumilus , B.cereus and B. halosaccharovorans ). Dual culture tests showed that B. circulans , B. cereus and B. halosaccharovorans strains had not inhibitory effect on mycelial growth of P. geesteranus . This study furthermore shows that sponge plugs containing B. pumilus contaminants were the contamination source in cultivation bags of P. geesteranus .

As an important part of biochar, surface functional group is the key interface between biochars and other phases, as well as an essential source of biochar's alkalinity and buffer abilities. However, due to the intricate organic and inorganic structures within biochars, the contribution from organic and inorganic matters to the functional groups remains unknown. In this work, the proton uptake curves were applied to study the functional groups of biochars via titration. Pine needle (PN) derived biochars with low inorganic content was selected for analyzing the organic functional groups variation under different pyrolysis temperatures. While rice straw (RS) derived biochars and the double-acid treated rice straw (DRS) derived biochars were compared for understanding the contributions from inorganic matters. The results indicate that the sorption behavior of proton onto biochars is surface adsorption, and the functional groups variation within PN biochars keeps consistent with reactions happened during pyrolysis. The inorganic matters within RS biochars contributed significantly to the buffering ability of biochars, and it is noteworthy to find that the contribution of inorganic matters of RS350, RS500, and RS700 on the total proton uptake stabilized at 67%, 84%, and 84% in the pH range of 2–8, respectively. As far as we know, this is the first report on separating the proton uptake ability of the organic and inorganic matters for biochars. The study on the interaction between biochars and proton will improve the estimation of the fate of ionizable pollutants, and the differentiation on the organic and inorganic matter contributions would benefit the understanding of biochar organic structures and inorganic structures.